I was a coach for team MRN and am now working in the eSports industry!
Livingston's Azubu Channel
Facebook: Ben Solganik
Currently: 2500+, Diamond Division 1
Season 1: 1900
Season 2: 2200+ Solo q, Triple Diamond
Tips for junglers:
Basically these are things that I am constantly thinking about through the course of a game.
1.) First and foremost is understand team compositions. Counter jungling because easier or harder depending on how your lanes match up. An example, if you have a nidalee mid and their team has a tf mid, counter jungling early is less of a good idea. Tf early with pick a card is much stronger than an early game nidalee.
2.) Understand common ward placements and how to get around them with champions that you play. Timing wards is also important. If you know when a ward is put down, make sure to gank in the seconds that the ward goes down. Generally, you can catch people trying to reward or catch them in lane. Bot lane wards generally are put down around 1:30-2:00 so good time to gank bot through tri brush is around 4:30-5 minutes.
3.) Learn all jungle paths so you can predict where the other teams jungler is. Also understand lane ganking. If their bot lane is pushed to your tower, many times their jungler will sneak into the side brush in order to gank when the lane pushes back out. If you understand this than you can predict a counter.
4.) Many times, counter ganking is more advantageous than ganking. People tend to overextend when they feel comfortable with their jungle there. Take advantage of this "comfort".
5.) If a lane is losing extremely hard sometimes you just need to forget about them and help others. There are points in some games where a lane loses so badly that even trying to help them will put them in a worse spot. Try to snowball the other lanes in order to gain some control back and allow the lane that is "lost" to play passive and minimize damage.
6.) Understand how much damage you can receive and deal. This is the most important part about understanding ganks and counter ganks. Know when you can when an engage and when to just walk away.
7.) Do your best to not make big mistakes early. Allow the other team to do this and capitalize on that. Early tower dives can lose lanes and snowball into losing the game because of that early mistake.
8.) Always click no. Teams throw all the time. Try to stay positive. You will win more often then you think.
There are other important things obviously but for people learning the jungle or wanting to become more experienced in the jungle, this should help.