Yeah, on your first back, swap out your yellow trinket with a red trinket. Then, try to use it on bushes when you get into ganks. When you go towards the lane, if they back off, just leave. If you think they know you're there, leave. Not worth wasting your time. If you're in bush, ready to gank, try to wait until they blow any cc/dashes as poke(assuming they're pushing against your laner) or at least wait until they go up to grab a cs. That's the best way. Watch your minions health, you don't want to be running into lane as they're getting that cs(you can, but not quite as effective), you want to be running in when they're going towards that creep to kill it(anticipate it, almost, but wait until they start moving to it).
The above is assuming the enemy laner is pushing against your laner. If it's going towards the other way(but not under tower) you can try going up the lane(from your side of map) into the bushes, and wait until you see an opening(I.E. blown engage/disengage). This is most difficult because generally waiting just for them to go for a cs isn't always enough.
TL;DR Wait until the enemy laner goes for a cs.