The #1 way to win your games guarantee a good time!
Is to say in champion select no matter what type of game mode it is wether its ranked aram, or one for all
"good luck team mates :)"
Ive been saying that simple phrase to my teams and Im winning more, my teams are nicer, and win or loose I have more fun with my games.
This is comin from a former toxic player who has had an account perma banned and gotten a 2week (a long time ago) on this account. just be positive and nice from the start and youll be less likely to rage etc, and your games will go better.
I cant stress enough how much saying that simple phrase and having a positive attitude rather than "oh boy bet i got the shit team again" has made league fun for me again