I started a similar thread in the lounge and got sent over here. I attended some shows and fairs in the last little while and have come to contribute my notes:
Photography is a rarity in the craft fairs. It tends to appear more frequently in the big art fairs. But I don't think this is really an issue, and that photography can still be marketed in this setting.
To be clear, these were tabling events and not tent-displays. Getting ready for a table is quite a bit different from setting up a tent. And from observing the illustrative printmakers, I would say that it IS better to have stacks of prints to flip-through (sorry thefizz), but to curate your portfolio carefully. Give them a sense for your work without overwhelming, and bring a few new pieces to every event. Having them at different sizes and stacking them accordingly allows your audience to see more or less your whole portfolio at once.
Use as much vertical space as possible. There is a local photographer who blankets his table with small prints, each lying flat, and it looks terrible. If he stacked them, who would have a whole table to use for other things, like upsell prints.
Also, there is no need to limit yourself to the straight print. My locals are selling prints to frame, cards, calendars, magnets, pins, flip-books, all kinds of stuff. I don't go for the magnets, and pins are just some kind of giveaway thing IMO, but having a little more choice and versatility is a good thing. Have something for everyone and offer a range of prices.
There's a bunch of logistical stuff to, like having things on hand to replace what is sold (depending on your setup), carrying sales receipts, and business cards, and having a nice tablecloth. Very important.