For me growing up, I had one teacher who required that we fill out a practice log she provided. She praised us for practicing daily and gave us the "eye" when we didn't. If we had a certain number of "full" practice logs we would be given a sort of gift card for a little music magazine she had. It was full of musical themed trinkets, etc... I like this but haven't found a good resource yet.
I am curious if you have any ideas or experiences you could share... I would greatly appreciate it!