Ideas that have worked for me:
Have a test track or power for anything you sell. Most shows have test tracks. If you take checks request their driver's license to write down their information. I have taken maybe hundreds of checks at shows and never gotten a bad one. However mail order is only US postal MO.
If something is bad find out now, let them see it work. Then it is their's for good..
You will NOT get your price for most everything but you will stand a good chance to sell something at some price.
If traffic is real busy I stand away from my table. Too many "I had one of these when....." non buying guys eatng up selling time.
Some lonely duds will chew off your ear.
If someone is really interested they will look and look and look at the item.
Buyers generally will not handle the trains. Tire kickers have no proper breeding.
Buyers treat stuff like it is theirs, cause it very well may be. I find buyers generally to be very coureteous. Nothing nice to say about hamfisted crude grabbers.
Have an assortment of ones, fives, tens, twenties so as to be able to make any change,
Five and ten dollar stuff sells easy, that four hundred dollar engine will go home with you at most small shows.
Use diagonally cut boxes under the table to display additional stuff for same table rent price.
Expensive stuff in center of table.
"You toucha my trains, I toucha you girlfriend" humorous signs work well. Problem is you might not want to touch the girlfriends of train grabbers.
Network!!!! Hand out cards with you name and contact info. Develope a following.
In the last half hour, when the show winds down look to trade off any thing you have for stuff you may want that you saw on other tables.
Bring the prospective horse trader to your table and ask them to look for what they will take for the piece of their's you want.
Sometimes the most profitable sale is the sale YOU cancel. Some people are more trouble than the sale is worth. tt