we used to make a printing block out of a potato- an adult could help a smaller child cut a pattern. You can do an initial, a shape, or something more elaborate like a little Christmas tree, a hat, a mitten, flower, car, airplane(!) whatever. You cut the potato in half and carve on the "face" of it- ink or dip the potato surface and print- repeat print to make a gift wrap or print on cards. If kids have never block printed, it is fun. Then you can wash and use different colors - overlap to make different colors and patterns.
Then draw on them too if you want to add details.