Player's Own Creations

I love it when players make up stuff for the campaign that they are in. To help encourage them, I give them bonus experiance everytime they create something. The reward is based on how impressive the work is and how much work they put into it it. For example, a ten page story about your character would net you 1000 or 1/20 of the total experience you need from one level to another. (Whichever is larger) While a haiku while net you about 25 experience points. (Unless it is a really good one)  I know 1000 experience points sounds like a bit, but I cannot think of a class that would level up with that number on the top of my head. If they go all the way, however, (like a live-action movie) then experience points will not suffice. I would have to give them something special...and maybe some self help books...