Just kite the jungle monsters in the begining, use your Q+AA combo.
golems -> red buff -> turtle -> gank(bot/top) -> blue buff -> turtle -> gank(mid or (bot/top)) -> etc. and try not to engage gromp before the Bloodthirster.

Use your Q + Autoattack combo as much as possible.
When ulting sometimes it's better to cast E before the ult.
When ganking don't lose your passive buff. Try to be sneaky don't get hit.
Stack your jungle item as much as possible.
Position yourself in fights.
If there is low possibility of getting away from enemy and it's impossible to kite just do a man mode.

This is my first guide and I hope it helps you :D