One of the best ways to fix it would be a functional report system which is somehow riots last priority and has been broken for nearly 2 years now.

Get the people who are tilted out of ranked for the day. Get trolls banned from ranked for 1 or 2 days as a warning. Only god know why riot is hell bent on making sure the playersbase suffers from these things as long as possible.

Their priorities are pushing skins more than it is providing a good player environment and no one is somehow bothered by it? Why is the report system not fixed? What's the reason for a million dollar company to not be able to ship a working report system even after 2 yrs?

Other would be a honor system. A player with high honor would receive a skin chest at the end of every month (duration is upto them). It has to be something really substantial for players to really feel like they are missing out by being dicks.

Riots priorities are like a basket ball court's floor is broken but they are more focused on making different colored basket balls more rather than fixing the broken floor.