Or just not playing Riven ever. Terrible champ to try to play if you're only at silver skill level, she's hugely item dependent and has a stupid high level of mechanics. If you can't get a lead with her, and you can't animation cancel, you're pretty much gonna get rekt.
Ryze is freelo doe. Wins lane, doesn't afraid of anything, and takes out half the health of the enemy team when clearing a wave. Level of mechanics is basically how fast you're mashing q while you casually hit the other buttons, and csing is as easy as eeq.