Complete Overhaul of the Honor System
When was the last time you cared about getting honor? I, personally, never have. It's literally meaningless. To be fair, there is a small chance of you getting a banner, what is sort of cool, but is that good enough for people to want to use the system? It doesn't do anything, and to be honest no one cares about it.
Now, imagine a world where your total honor would show up in champion select. It was there for everyone to see, something to be proud of and (to be honest, perhaps this is the most important aspect) to not be forgotten completely. That way, you don't need a banner to show off that you've been honored (and who has banners nowadays anyway?)
Even better, imagine if honor gave you IP increases. Let's learn a little from Dawngate and what they did right; being a good player meant good rewards. Sure, you give us a skin a year, but what about a game per game basis? What if someone with a banner got a +15% IP increase? That's a reason to be nice ingame.