I wonder when people will realize
Players aren't toxic, plays are. Don't make stupid choices, your team won't get mad. And I don't mean "Don't feed or don't be a douche", I mean, know your basics.
Know how to perform a gank as the lane AND as the jungler, know what your jungle needs
Know how to farm in your lane, be it top 1v1, bot 2v2, know how to do it
Know your counters, if you're playing Kat know how to plan around the CC kinda thing
Know how to clear a ward, know where to place wards, know to buy wards
Know how your teammates champions work, if you don't then ask, know what they need to play their champ
Know your champ, know their combos and how they play, know their laning phase to a point that doesn't hinder your team
Know your build, you don't need 3 warmogs on Malzahar,
Know your basics and your team won't be mean to you