Any time that I take on an RPG campaign, and I’m comfortable enough with the rules to feel confident, I start thinking of home-brew concepts and letting my players test them in-game. If they turn out to be unbalanced through gameplay, I’ll work on them until I have something solid for the campaign.
This is where I’ll put those concepts up. This is mostly for my players, so they’ll have a spot they can use for a reference or if they need to check something.