Big Brother made a Christmas Tree Geoboard with his foam cone; since I didn't want Little Sis messing with push-pins, I broke off the ends of toothpicks (so there were not so sharp and to make them shorter) and she pushed them into her tree.
Felt Christmas Tree:
I made this for Little Sis last year and was so excited to bring this back out!
Little Sis has not done this yet, but it could be used various ways. I printed and laminated two pages and cut out the lights on one of them so that she could match number. You could also practice counting and hanging them up for some fine motor fun!