Hi Heidi:
Here are some ideas off the top of my head:
stamp on white tshirts
Bingo game
abc book (they could draw picture/stamp letter)
bookmarkers add yarn tassel
shrink plastic make shoe charms or necklaces/keychain
stamp on magnetic sheet for fridge magnets
acrylic frames =stamp on CS & other half for their photo
you could make blank postcards & they stamp fronts
fun foam = frames or door hangers