Quests
I honestly believe that you should add in extra quests given this thing with Riven and Yasuo just came out. Like every day, give the player random quests that give things like bonus IP. And maybe a few special things after they've done enough of them. It'd give people an even bigger incentive to login every day as to finish those quests and get something that they may want. Kinda like Smite, really, with how they give you quests for bonus favor (I.e. Playing a certain amount of matches with a specific primary class.). I'd REALLY love to see this as a feature in the future. Or at the very least considered. I love playing League of Legends, and having quests for bot and normal players alike to do would be a wonderful way to have people play more if they really want a champion.