Christmas fair countdown tip
Consider creating crib sheets
The point of this ramble is because you have to figure that the temporary nature of a craft fair works against this behaviour. If someone doesn't instantly buy a product, they can't come back the next day to buy it. And by the time they have walked around the whole fair, looking at all the other lovely stalls, they might forget about you entirely.
So, to try and get yourself in people's minds, as well as allow them to consider items at leisure, create a catalogue or product sheet with details of what you make and how much it costs.
This only needs to be a sheet of A5 or A4, with your items listed nice and clear, ideally with pictures. Include a line or two about the product, along with dimensions, so the customer has everything they need. And obviously, link back to your Etsy shop!