I've been doing craft shows. For 17 years and there is no right thing to sell. You have to have a variety of items and prices. Like the lady said team items always seem to sell, I think its because crafters don't make items with men in mind so wives and kids buy anything that's got the favorite team on it. Check around because there is usually more than 1 team that sells well. Christmas ornaments do well. A lot of people buy ornaments as gifts for their coworkers as well as family and friends. Always have something you can let go at just pennies, children love to buy for their parents and if you have something you can let go for whatever they have, you'll. Get the parents buying from you too.