Opt out of lobby.
We all know these games where someone troll picks Soraka top because someone banned his precious Yasuo or when someone picks Janna jungle because stealing drakes with twisters is so OP.
When you are in your promo's it is especially annoying when you are unable to dodge and left to play with what you get and I think it's not fair to lose a promos game for dodging when your team is clearly troll picking or whatever.
So my suggestion is an opt-out system, where at least 4 players chose to opt out of a game and the game making is canceled without being penalized with a 3 lp or promos loss.
Now I hear you say, yeah but then if you don't like the enemy team you will just opt out and find another game. I say limit your opt-outs like aram rerolls are limited. Why is it so bad for people to be able to get out of a bad game every once in a while? Why be forced to play troll games? Okay maybe this idea isn't polished off yet, but with some input from the community there might be something to think of.
At least let people dodge 1 promo game without penalty.