Oh sorry Jacque, I didn't notice this post!
I only do doll craft shows, so they're only 2-3 times a year (which is for the best really, cause it takes me about three months of sewing to get enough stock up for the market whilst working on my store!).
I am probably a different case because I'm quite involved in the local ball jointed doll collecting community. We have meetups once a month, and talk often online, so I'm always in contact with my customers. So leading up to the market I spend some time posting up teaser photos of things I'll be debuting at the market, to get some interest going.
So if you know people in your local community, maybe getting in touch with them via FB or something is a good way to keep a loyal customer base. Maybe hold off on a new soap or something until your next market, so that they feel special by getting to buy it first!