Our initial idea was to let the kids paint 3 boxes white.
Then we would attach them together and glue on eyes, nose, buttons, etc. As we were painting the boxes and listening to the children, we decided not to attach them together. We cut out eyes, nose mouth out of felt and foam. We attached Velcro to the back of the pieces and to the boxes themselves. This allowed the children to stack the boxes as they wished and put the features on as they wished.