Thanks, Jonathan. I've always given extra experience points for clever ideas, role-playing, world building ideas, actions, and questions, etc... If the class-specific action furthers the game or the PCs goals, xp is awarded e.g. a particularly clever use of Hide in Shadows, a proficiency, or magic item creation.
I think I had a blanket 10% xp for treasure, but I'll calculate the adventure I'm considering and see if your method works best. I hope for two adventures or so per level.