If you have a feeder or troll in your team
Instead of flaming or giving sarcastic remarks I tried new tactic and surprisingly in most cases it worked, so I share it with you.
Any time a guy begins like 0/3/0 warn him that he will be reported for Intentional feeding, don't insult, don't flame, just **warn ** him. Don't tilt him by anything else, but warn him. Surprisingly dudes become more careful after that.
Now if you have a troll who tells " I don't care" , "I am gonna die" etc or w/e trolling in other ways, tell him "Fine, I will lose one game because of you, but you will be suspended for 14 days or you will lose your account for good".
Yesterday I had a game where troll was not helping a team and openly declared that he doesn't want to win. He wasn't feeding but cleverly was doing things for us to lose the game. After telling "Good, RIOT reads chat so you will be suspended for 14 days", guess what? In the last decisive battle he joined us and we won the game.