Here I'm going to explain what I do for some matchups in the jungle.
jungle is pretty easy. Invade his red and pressure him early, as he's very fragile and can't duel you well. Be mindful of his passive and dodge his knockup in fights. A randuin's is useful if he gets out of hand.
is dangerous left alone. Steal his red or even his blue if you're manly enough, and keep the pressure on. Invade him frequently and countergank often. You need to deny him as much exp as possible, so take his buffs and farm and then reverse snowball his ganks and end it before he can get tanky. If lategame does happen, do whatever you can to keep a teamfight from breaking out.
is really easy. I don't think I've lost to one yet in ranked. Invade red, make sure he doesn't steal, and pressure/kill him early. Pretty standard procedure. Be wary of his Feast during post-6 fights with him if you don't know if it's off cooldown, and dodge his Rupture and Feral Scream in duels. Keep him out of Baron/Dragon fights if you can; he can outsmite you with his Feast+Smite combo.
jungle isn't very common. He does a lot of damage early, so don't fight him unless you get the jump on him and/or he's low. His ganks are fairly poor, so if you can deny him farm and screw up his ganks/get your other lanes ahead, he'll have a really hard time. Beware his team backing him up in the jungle.
jungle is also uncommon now. Standard invade and denial tactic, but know she has a power spike at 6, especially with ganks. She is skillshot based, so stay to her left to avoid getting hit by the arc from her Q. You should win this fairly easily.
is a champion where I would start at my red and have my team watch blue, due to his nature. He will typically start at his topside buff, invade yours, then gank top or middle. You may choose to mirror his movements or secure your buff immediately to deny the invade and either countergank or tell your laners to play safe. He literally kills himself during his early clears so you can kill him in his jungle very easily. He cannot duel you early and lategame he's little more than a walking meatshield. Your mobility and pressure should keep him from being a major asset even if he eventually gets some items.
can be tricky, but usually she's not too bad. She has a weak early clear, so invade red and farm while looking for an opportunity to gank, Dodge her stun and slap her with phoenix and she will struggle.
can also be annoying. Her slow and chasing can really be tough to deal with and she can walk over wards. If you take her blue she's really crippled, or you can do the typical red invade. Starting your own buffs is also not a bad idea. Watch your lanes to see where she'll roam and be nearby in case she jumps out. She relies on roaming so if you can keep her from snowballing she falls off hard. Steal her creeps when safe to do so. Early oracle's can be helpful here.
can be annoying. Fighting him straight up is difficult due to his fear and drain and his silence can impair your stance swapping. Don't fight him straight up unless you know his fear is on cd because otherwise he'll just chain cc you and his team will murder you. Useless if you take his blue; taking his red is safer but he isn't set back as much. Ward everywhere, including your jungle so that he can't get a good gank off with his ult.
jungle is weak. His passive applies a slow so even without red he can sort of chase but his ganks kinda suck anyways. Invade red and stomp on him early so he can't snowball. He can orange out of bear stance though so be mindful of that, though you still win a straight up fight.
isn't so bad. Weak early clears as per usual and his invades are lackluster compared to yours so take his red and you'll be fine. He can pull off ganks as soon as he has his E and they get even better with his ult, though, so be mindful of that when ganking/be ready to countergank at a moment's notice. Ward around all your lanes and his jungle so you know where he is.
Lategame he becomes a very powerful initiator and splitpusher as well, so make him suffer early and force a fight or baron if you see him separated from his team to keep him from stomping you late.
is annoying. He's got some decent ganks and mobility with his flag and his ult can screw you up. He needs red buff to gank well before 6 so take it and exploit his squishiness. Counterganking can be hard because of his flag and ult, so you should bring the fight to the other lanes and capitalize on your mobility to pressure objectives and snowball your lanes so he's forced to run around. The key to beating him here is to make plays faster than he can deal with them.
is also irritating but he relies on red like many other champs to follow up his ganks after his stun and jump. He can just stun you and leap away if you see him in the jungle so a duel is ill advised, but you can invade and counterjungle him effectively. A good way to deal with his ganks is to bait his stun and leap, and then cc and wear him down while he can't stun or jump away.
His lategame is a lot better than yours if it comes to it, so if he gets to be a problem, push hard to force him into farming waves constantly away from his team to keep some pressure off of yours.
jungle is very rare; I think I've only played him once. Steal his buffs as per usual and deny him farm. Counterjungle like crazy. He can gank with his wall and finish them off with his ult. If you catch him in his jungle, he's screwed. You're too fast for his skittles to hit you and as long as you kite away from him after you hit him to avoid being melted by his E/don't get stuck in his wall, you're golden.
jungle was FotM for a while, so you don't see her much. She can't gank without red so take it. She can kite you for days with her slow and speedup combined with her E, so be mindful of that, and her ult can bait you into making some bad dives and turn fights around. Stop her from farming and get your lanes snowballed faster than she can keep up, and fight her when her E is on cooldown.
jungle is VERY squishy early, so exploit that. He has some cray damage when people are isolated so don't let him utilize the brush in fights, and you should blow him up.
If his stealth is getting problematic, pick up an oracle's or pink wards so he can't refresh his passive or kite you. Lategame he can instagib a carry but you should be too durable for him to burst. If you have to fight, it's a good idea to peel for your carry and stop him from blowing yours up.
is a good matchup. Secure your own buffs instead of invading, and farm until you have to countergank. You are one of the few champions that can outduel him early and who can turn his ganks around. Dodge his Q and be mindful of the slow from his E, and you'll be fine. You're much more useful lategame as well. All in all a favorable matchup.
can be tough. He's weak early but fighting him is annoying due to all his cc and armour. Steal his buffs and counterjungle and get some ganks off before he hits 6. If you get far enough ahead he'll be too squishy to stand up to you and you easily outspeed him. Lategame his ult is ridiculous so keep tabs on him and force their team to chase you so you don't get initiated on and swept.
is a jungler that I don't have much experience against. His ganks are very strong with his root, though, and he has a spammable knockup and good base damage. Like always, you're a very powerful counterganker and will melt him early. Jump on him after he uses his W and he's screwed. Don't fight in his ult if it can be avoided.
is irritating. Steal his red and focus more on keeping him behind as opposed to snowballing your lanes. A fed yi will splitpush harder and outdamage you, as well as his resetting giving him better teamfight. You can stun him when he ults and kill him easily early, though.
can be deceptively difficult. Susan's wither is what makes him more difficult than usual, as he can gank very well with it, as well as screw your mobility over. He's easy to invade so do that and then apply pressure on the map away from him. Susan is slow, so if you avoid him and make things happen where he can't reach you, he'll have a hard time doing much of anything. If you fight him, stay out of his E and get some early tenacity to deal with his W, and always be mindful of his ult. You should win this but if you get caught by his W constantly you'll get behind.
is my other main and fairly easy early. He's slow and usually starts blue; if you can take his blue he's screwed. If you can't take his blue, take his red and gank. He doesn't gank until level 4, and his chain CC is unrivaled, so do not let him get to level 4 smoothly. He cannot fight you early, but he can chain cc you until his team can help him, so be aware of that before you engage on him. His ult has a stupidly long cooldown early on, so take advantage of that and bait it out if you can do it safely. Bodyblock his Q if he tries to escape or jump on an ally; it has a longer cd when it doesn't hit terrain and he lacks the mobility to get around you.
is irritating. Do the standard red invade strat. He can gank from 4 and on with his fear but he really gets annoying with his ult. Ward well and don't let him snowball. Nocturne is capable of counterjungling you as well, and he may contest your buffs when he notices that his are stolen. Alert your team if you see him hit 6 before he ults. You beat him in a fight unless he catches you while you're low. He can spellshield bear stance.
gets his power from his counterjungling. Secure your buffs asap; he will invade. His consume and smite is excellent at stealing buffs and objectives; pull your camps into the brush to prevent a flash steal. In fact, pink your brushes so you're sure he has no vision, and be at your buffs at the respawn time on the dot. Nunu's ganks suck though and he thrives on disarray, so if you catch and kill him in your jungle and get the other lanes snowballed, he can't do much. Do not contest dragon or baron with him around; he will steal it with his Q+Smite. Nunu has good chasing power with his Blood Boil and Iceball, but is terrible in 1v1 fights. You can bear to disrupt the ult channel.
isn't so great anymore, but don't underestimate him. He likes to build tanky and dunk people with his true damage. He relies on his Q and red buff to chase, so juke his axes with your speed and deny him his red. Don't underestimate his true damage when you duel him; it really freaking hurts. You can counterjungle and outgank him, though, as well as pressure the map more. Avoid 1v1ing him when his Ragnarok is activated, and remember that his passive's aspd buff is inversely proportional to his current hp.
can cause problems if the player is competent. Dueling him can actually be difficult with his taunt and defense. Some Rammus players are very aggressive and will do roaming powerball ganks frequently. If he ganks close by, counter it and then counterjungle or farm. If he ganks from far away, gank a lane that's close by or take all his camps. They'll quite often prioritize their ganks over their buffs, so you can steal them and then gank a nearby lane to pressure him if he's not on with his timers.
isn't so common in the jungle but you can sometimes see him. I'm not experienced with this matchup, so I would secure my buffs and wait for an opportunity to gank. Care for the brush because of his passive, and get pinks and/or an oracle's for your lanes when he hits 6; his stealth ganks are powerful.
is also a rare jungle matchup, but you win. She is mobile and has decent damage, but she relies on her Ki Burst to gank. Deny her farm and countergank as usual. She does have good damage early and might actually start red. Plan your invasions wisely.
is easy. Invade red etc. She has a powerful initiation with her ult, but it has a long cooldown. She can't fight you in the jungle, but be aware of her slows before you get tenacity. You dump on her.
can go either way, but you have the advantage. Secure your buffs first and countergank him. A smart shaco may even send a squad to invade one buff while he takes the other; do not fall for this or go on a wild goose chase. He falls off really hard if he doesn't get fed, so the early countergank is very important. Once you deny him his kill, camp him in his jungle. Do not fight him if he has red buff and you don't, and watch for his boxes. The goal here is to eliminate his pressure from the map to make your lanes easier, and even force their laners into the jungle so you get free kills/towers.
Shaco can take dragons as soon as he has dreds and his clone, so keep it warded early.
Protip for the clone:
the real Shaco will have buff auras around him and the clone will ALWAYS deal less damage and take more. If you have trouble seeing which one is real, see what one takes less damage, and focus it.
has the slowest clear in the game. Invade and deny him farm so he can't ult. Dodge his taunt and he has no chance.
is also annoying. She's a good counterjungler like you, but she's red reliant and her ganks suck. Secure your buffs and ward her jungle, and gank lanes she's away from. While she's poor at initiating a gank, her damage makes her counterganking strong. Stay on top of your camps so she doesn't clear them and counterjungle her when you can.
has good clears and powerful ganks post 6. Take red and pressure him. His Q only slows after he hits someone with it once, so bear that in mind. If you can break his shield, he loses his mspd buff as well. You can shut him down early.
jungle is actually pretty strong. He's a powerful duelist in a 2v2 situation, and his stun and heal make him deceptively durable. He is actually not hindered very much by counterjungling due to his auras and kit; however, he has no kill potential without red. Take it and take advantage of his slow speed.
is trouble. He is the one champion that counters you in the jungle, especially Tigerdyr. His chomp reduces your damage whilst buffing his own, so he can actually duel you and win. His counterjungling is very powerful, and his AoE makes fighting him even more dangerous, whilst his E can cockblock you from escaping or getting to your team. Trundle's ganks are relatively weak and teams with a lot of poke and CC are effective against him. I do not recommend taking Udyr against Trundle, but it is winnable if you avoid him and get your lanes ahead.
is a joke. Stupidly weak early and has poor clear times. Apply pressure on him and kill him early and often and he has no chance. He'll be forced to ult trying to run from you, so he'll be useless in fights. If he does get out of hand, get a randuin's and keep him from splitpushing.
is interesting. If you're playing normals and get a mirror match, you want to secure your buffs and farm. Udyr is unpredictable because of his versatility, so just play it safe and wait for him to make a mistake, then punish him for it. If you get the level advantage, you should be able to beat him quite soundly. A lot of Udyrs just build full tank and stick with their team, so take advantage of that by splitpushing and fully utilizing your ctrl+4 whilst taking towers. If he goes tiger stance, avoid fighting him early as he outdamages your phoenix, and dueling him without a health+level advantage is ill-advised. You can counterjungle him if you see he's not nearby, but be aware he's just as capable of counterjungling you in retaliation. Ward your buffs so you can see if he tries to steal them.
is tough. She's got better ganks, can survive in duels, and can counterjungle.
You can either secure your buffs or take her red, but you need to be cautious. Vi has trouble fighting you early, but as the game goes on, she becomes more dangerous. Bait her Q and she has no escape, and if you're there when she tries to gank, you can turn it around if you blow up the carries before she can do anything. Don't let her get red buff.
is dangerous if played right. He is a capable invader, and he excels at dueling. A good bear will invade so secure your buffs and farm. Countergank when you can, but his flip and bite are very dangerous, so you have to be on the ball with them. Do not get into an extended fight with volibear when he has red; he can just tank you with his passive and when you get low, he'll flip and eat you. You need coordination to bring this guy down if he's good. Fight him when he doesn't have his passive (it's on a 2 minute cd) and do not fight when you are at low health. Splitpushing is effective.
is ancient and doesn't do well against you. He has mana problems without blue and no killing potential without red unless he has his ult. He can survive in duels due to his sustain, so just counterjungle him and be there when he ganks. Stun him out of his ult and you can turn on him very easily.
is a strong early ganker. Secure your buffs and be there when he ganks, because he ganks early and often. He's very dangerous with red buff, and he can hold his own in a duel with you. You just want to deny him his early kills so that he falls off and then steal his buffs and force his towers down.
is difficult. He can start at either buff, so be cautious with invades. His ganks are devastating, but you can out duel him if you catch him. You can stun him out of his E channel if you see him winding up. Don't get baited by his passive. He does best initiating fights, so keep their team scattered.
is usually pretty easy because he's so squishy early. He'll die if you look in his direction. Counterjungle him often and mess his ganks up.
Respect the damage he can do with his ult up, though. If he drops a mark on you, juke him and avoid fighting until it goes off, hit up your laugh, and then detonate him.
If you can bait his shadow out when he ganks, he's dead.