In my opinion, I would just ask my child what they think would be a super silly hat or sock. This is a great opportunity for her to get creative/artistic. It should be a fun activity for the children, not a creative mom contest. I've seen this stuff get way out of hand at my daughters preschool where they had to make posters about themselves. It was obvious that most were done by parents. Ask her what she thinks and then try to accomadate her imagination with supplies to create it and by all means help her if she needs help, but let her take the lead. Also, I don't like the idea of the "prize" either considering that a hat created by a parent might win instead of an authentic child's creation.