Ann
Is this your first time doing these shows?
Some advice before you apply:
1. Find and join ArtFair Insiders. It's a web resource where artists report back on art fairs, mostly outdoor mixed art and craft fairs. You can use this to contact other photographers and see which fairs are best for photographers.
2. Be careful to check what people make as you consider online reviews of fairs. An event that is great for someone making beaded earrings may not be good for a photographer.
3. Go to the fair's website and look for a listing of previous exhibitors. You may want to ask a few people how well work in your medium does at that fair before you commit several hundred dollars, and several hundred hours to applying, prepping and attending a fair.
4. Look at Yelper and similar reviews of the event. Who is reviewing, what are they expecting, buying, saying?
In general fairs that are more than 20-30 % craft are difficult for painters. They can be a little better for photographers, but you also need to be wary of too many photographers. I tend to avoid anything that sends out a prospectus or solicits artists with photos of ugly overdecorated teakettles, the same old handmade aging hipster jacket/cloak, and/or delightful little urchins having their faces painted. Sound like a lotta fun, but I'm looking to sell art, not eat hot dogs.
When you've decided to apply, your booth photo should look like your actual booth. And your booth will do best if you have at least on eye catching large "magnet piece" to draw people in, and lots of smaller things for them to buy. I generally do a large eye catching magnet piece right up front to catch traffic and another in the back to bring that traffic all the way into the booth.
Bin items are a good idea. People will buy things out of the flip bin instead of the identical item at the identical price hung and framed. They like to touch stuff, I guess.