The passive is very important, the minimum acceptable is 60 bells, the ideal is between 75 and 95. The more the better. As long as you have returned to base, it is good to collect the bells that are on your side of the jungle. When you go to war you can collect the ones that are in the river. The mana it provides keeps you in line for quite some time. Try to go out of line when you see fit: when the enemy adc and / or support go to base, or after having killed one of the two, or when you are alone in line. You can also try ganking other lines. Just remember that you cannot go offline if you are not sure that your adc is going to be fine.

Pokea using the Q on a minion / wall and the adc, or the enemy support, or in both (the best of situations), from there proceed to attack a basic with your meeps: this is the most effective way to poke. But be careful, also be careful of the damage you receive, there are times when it is better to stun and not attack.

Whenever you can, leave a W on the line, under a tower or in a bush, every time you advance or consume one of the shrines, put a new one. Leave them under the tower if you see fit.

The E serves in many ways, you can help your jungle to gank, to get out of trouble, and if they follow you when they come out of the tunnel it is the best you can do and if they are under a tower better.

The R is the most difficult to use, because you can stop something that was won just by saving one of your teammates. Use it when you see that you can really save it without making things worse, ex: if the mid is only in a 2v1, and your jungle / top or even you are coming into line, you can use it without fear, to get some time or take out combat to an enemy for the mid to reposition or exit. But in a TF, it is something else, the fear of ruining it is always present, but losing that fear is in practicing. Try to take out someone you think might annoy you. You can take out any enemy that is out of TF, those 2.5s in which he does nothing help a lot. You can also start TF, when you have an AoE team (Damage in area; it would be the best case), so that they position themselves and destroy the opposing team.