Make it fair for everyone: Chance for a random LP drain after each game.
Since afking, trolling, feeding and general free LP losing in ranked is such a big part of LoL and is so important part of gameplay (since riot does shit about it seems they like it that way) i have an idea how to make it fair for everyone and give it a bigger role.
After every game let everyone roll a dice if they will lose bonus LP (20+ no matter if they win or lose), since getting an afker is tottaly random and riot does nothing to fix it, lets even the chances of random free LP loses in LoL so climbing in ladder is equaly frustrating experience for every LoL player.
Instead of trying to fight those cancer behaviors with useless Leaver Buster or whatever pointless ideas riot comes up lets just make it a common part of gameplay and deal with it.