And I'd add: Have someone in the booth at all times, no matter how slow it gets. Nothing like being interested in something you see at a show and sure enough, nobody in the booth to ask about it.  If you're working alone and need to take a facilities break, put up a sign telling the approx. time you expect to return (not "5 minutes" or whatever, state "Back @ 1:15"), and make it as quick a trip as humanly possible.  That might be your best sale of the show standing there reading your sign.

Good Luck!! Hope it goes very well for you. We enjoy going to the shows, and always try to go on one of the first days of the event, before the exhibitors get worn out and lose their enthusiasm. It's harder work to sit in a booth all day and smile than it is to work!