What part of the country are you in? Make something that fits the area. I do a show on the water, so I lean toward nautical, boats. I found prices between 10.00 and 25.00 sell the best.
I just signed up for one May 15th, witch city, guess I better go look for witch patterns :)
I too cover my table with cloth to the ground. Years ago I found white demask tables cloths for $5.00! Now these are old, one has a stain I make sure is covered, another a small hole again I have it covered.
Good luck! Oh bring extra tags in case you want/need to change a price.