Just farm under tower and hope your team wins there lanes. If you choose to roam and it costs you a tower, you better hope that roam was worth it and that you outtrade the objectives in the long run.
It's possible to to avoid the E, just keep moving. Immediately disengage with your shadow to be out of range of the Lock on Q's if you do happen to get hit.
Don't pick Zed into Urgot.
If you get bored farming under tower or somehow manage to die under your tower.... Know thatYou have some of the best tools to farm under tower. Your passive lets you last hit caster minions after they take a hit from the tower. Not many champs get to do that for free! think back on all those mages that had absolutely nothing to deal with you and tell yourself "Fair enough" :P
If he's pushed you to tower he's an easy gank as he has no escapes.