i have done craft shows for over 20 years, too...Hen3rietta and Lori S have said almost all. I agree with everything they say. One thing...if you do an outside show...please make sure you weight down your tent...a gallon of water per leg is NOT enough...I have seen those tent rolling over the top of other tents.
With indoor shows...don't have too many different different types of things in 1 booth ( floral, jewelry, quilted items). The customer can't decide what catagory you are and often walks past.
The shows are not recovered yet from the recession...some are OK, others not good at all. I had one this year that I made the show fee back and my gas money...so, that means that I gave away my merchandise.