Encourage Positive Behavior By Rewarding Honors
Why not give a small amount of IP as a reward for Honoring players?
This would hopefully bring back the honor system, which I've noticed has really fallen off in the last few months.
The amount doesn't need to be large. 3 or 5 IP would still add up over time if you're able to get it for the first person you honor after each game.
It might be a bit of "bribed sportsmanship" but I feel like it would make post-game a bit better.