Playing mechanically intensive champions

Expectations:

https://m.popkey.co/80a186/wqdmb.gif

Reality:

http://www.lolriot.com/wp-content/uploads/2012/10/Pounding-Keyboard-GIF.gif

Seriously though, I'm trying to learn Riven. I've always wanted at least one mechanically intensive champion in my roster, but I can never get the hang of them. I am really enjoying Riven though. Even in the games I lose, I feel like I accomplished something.