This is not my idea, but I have seen teachers use it and it looks fun. I teach music, so it wouldn't be practical for me.
What they do is have the students earn each component of something...for instance, a banana split. You could "assemble" the reward object maybe a piece at a time on a bulletin board. So many points would earn the container, so many more, the first scoop of ice cream, etc. until the cherry on top and last the spoon. When all components are earned, they get a "party" with the real thing.
The banana split is just an example....I think you could do it with almost anything that has different "parts".
Diane Woodward
"Cadenza"