When my in laws used to do flea markets, swap meets, rattlesnake round up and such, they had many small items that could sell for $1 - $5.
One very popular item was the (1/2) dish towel with the hanger for the refrigerator door. Potholders sold well also.
I would think that cute pincushions might do well.
Not sure what kind of pricing would be appropriate now for that sort of venue. Do know that people are looking for very cheap (garage sale prices).
You will most likely be able to get better return for your investment of time and materials at craft fairs than at swap meets or flea markets.