There are a couple kinds of junglers
Ganking junglers = very strong early game, get fed from kills and gank lanes often. (Shaco, Vi, Jarvan IV, Lee Sin)
AFK farm junglers = farm early and mid game for a strong late game, usually tanks or devourer junglers (Master Yi, Warwick, Nasus, Cho'Gath)
Bruiser junglers = A combination of the two above, usually strong mid-game teamfighters with frequent ganks followed by short bouts of farming
Tips for your 3 preferred champs:
-Favor a lane if your lane teammate has very strong offensive capabilities since you play CC heavy tanks.
-Farm until mid game since your champs are meant for teamfighting
-Make your enemies paranoid by ganking a lane twice, and then leave to farm while they're still nervous since you have high mobility but can still go back to farm due to high hp/sustain as well. (don't overstay or else you'll fall behind)
-Counter-gank the enemy since your ult alone can change the tide of a teamfight
-Use your ult to trap enemy under friendly tower for an almost garenteed kill
Jungling Etiquette:
-Do not tax minions if you get the kill unless you are pushing down tower
-Take 1-2 minions for a failed gank if it wasted a lot of your time
-Do not take any CS if you fail a normal gank and didn't lose you or your laner a significant amount of health/mana/time
-Try to let your laner get the kill if it will snowball their lane/ they are behind 1-2 kills
-DO NOT IGNORE FAILING LANES IF THEY CAN GET BACK IN THE GAME WITH THE HELP OF A GANK
-Take 1-2 minions if you assist in a successful gank
-Do not push a lane if your laner is falling behind or getting ganked a lot
-Push laners wave to tower if they are winning/if the enemy is far away UNLESS your teammate is trying to freeze lane
Farming in the jungle:
-Steal enemy camp buffs by smiting them (not killing them with smite, just smiting them when you walk by)
-kill enemy large raptor, leaving them to deal with high-damage low-exp small raptors
-Back as soon as you have enough money for your lvl 1 machete upgrade
-If lanes are going well and enemy isnt counterjungling you then just farm, farm, farm
-Watch map for enemy jungler, if they're top then take their bot jungle visa-versa
-Ward behind walls in your jungle when taking crucial buffs to avoid an enemy steal
Ganking:
Lane gank: When you sneak into the lane brush from behind your tower (avoiding enemy minion vision) and attack once your enemy over-extends.
Diving: Either tanking enough tower shots for your laner to kill their opponent or killing an enemy while they think they are safe to recall at low HP under tower.
Counter-ganking: Predicting or spotting an upcoming enemy gank, and then laying in wait for the enemy jungler to "surprise" your laner. PING IF ENEMY IS IN YOUR JUNGLE, THIS IS ALMOST A 100% KILL WITH TEAMMATE HELP.
Counter-jungling: Warding an enemy buff and waiting until they are at low health and killing the enemy jungler/taking their buff. If the enemy is a jungler that starts at red buff (Lee Sin, Kha Zix, Rengar, etc) then use this knowledge to steal their blue buff or other unattended jungle camps. At around the ~7:20 minute mark, sometimes the enemy mid laner will go to recieve a blue buff from their jungler, this is a very good time to steal the buff as well as usually pick up a kill on the enemy jungle as they will likely hve been tanking the blue buff while waiting for their mid laner. Killing enemy junglers who attempt to solo dragon at early levels is usually some free gold as well although uncommon.
A lot of the uncertainty you face about when to gank and when to farm is due to lack of game knowledge. You need to know when to push lanes, when to take objectives, which lanes are losing/winning, how to keep track of the enemy jungler, how easy a lane will be to gank, when ganking will result in a kill, map awareness, when ganks aren't worth it, and be comfortable and familiar enough with your farming routes to go back to farming and counterjungling like a second nature after pulling off a quick gank or shove. After you have a basic understanding of the jungle meta-game then you can start focusing on more advanced skills like level 2 ganks, level 1 steals, getting specific lanes fed, sneaky gank routes, alternate jungle routes, controlling and zoning objectives, counterwarding
