Shouldn't put buttons on them (choking hazard) but these would be easy to do from felt or blanket material. Like the jingle bell inside. cute little baby rattle. free pattern and you use jingle bells for the rattle part.
this is another idea I saw in that client's house. Useful for stuff besides babies, of course. They don't want to stay all day in those little baskets anyway. Sweet idea for baby organization in a closet. You could even use it as a changing station.