I live in a small town too and in my experience I suggest you book early for shows because some event planners do not want two vendors with the same merchandise. (Maybe it's just a small town thing because we have limited space available at events). This is also true in some consignment shops.
Anyway, it is important for me to book shows early and tell the hosting person how much I enjoy doing their event and that I want to keep my spot or what spot I'd like to have. If they walk around at the show before, during or after the event...be sure to say "HI" and get to know them. It helps for them to be your friend. Last year I hunted for shows and this year they emailed me to ask me to join in! Plus, event planners often give advice on vendors to other event planners. You may get invited to shows you didn't even know about.
I paid for all my summer shows early. Last year I had to inch my way up Main Street to be very near to the center plaza where everyone is eating, drinking (drunk people buy more...lol...it's true) and dancing. The first show in June last year I was far away and then each month after that I asked to be a bit closer. She finally told me that this year she would give the really good spots to those who were in the show last year. So, I had a few bad shows last year but this year I "earned" my good spot.
I could not be at the show in May because I was going to Disneyland so I called and told her that I'd still pay for my spot, in order to keep it, but I wanted to let her know so she didn't have a gap in the vendors. She thanked me and said I did not have to pay for it and that I could have it the rest of the summer.
Lastly, be super friendly to your customers. If you are familiar with them most of them will buy from you rather than a new-comer.
I hope this helps!