If I'm top laning with Riven, how should I keep my lane from pushing? When I go to harass with E-W-Q or whatever, everything does AoE damage and hits the minions, not to mention myself getting aggro from the minions so mine survive longer.
If I try for a kill or something with ult and they manage to get away and heal up, my minions are pushed all the way to their tower and they can just farm underneath while I'm super susceptible to jungler ganks because I'm overextended. Sometimes the lane stays pushed for a long time and I just lose all momentum I could have gained from harassing them.
So how can I prevent pushing the lane in the first place, and how can I fix it if the wave does get pushed?
Riven's mobility and shield from E allows her you turret dive exceptionally well, if the enemy is at low hp (assuming this since you said he survived your ult) you can let minion to come in, then you just walk straight up to him while the minions are tanking the damage. He either need to back off or your kiburst and damage will allow you to score an easy kill on him.
One ward is pretty much all you need for Riven to escape ganks, her Q and E combine allow her to close a lot of distance to her turret.