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.
Celery flower art is another great Mother's Day idea or just a simple art project for the classroom. I think the idea of using food to create art would be an interesting project to bring to the classroom and have students work with and experiment with.