thumb prints made into Christmas lights. Easy craft to do with the kids. To enhance this, I might extend the strand each year, so by the time they are older, you have a long string of thumb print lights.
Thumbprint tree - with salt dough and a christmas tree cookie cutter. I thought it would be a neat keepsake with a child's thumbprints and first name and year. (This one is a family thumbprint tree and is made of ceramic)
Use card stock and misc buttons to make your own Christmas cards. The card stock can be bought at Walmart, etc. or at most any craft store. The buttons come in bags at most craft, hobby, or fabric stores.