when i do festivals outside i always burn oil or a few jumbo sticks of incense in my booth..usually butt naked because it's a sweet smell and it travels far. i have people tell me that they could smell my booth from far away, and they usually buy what i am burning. i don't know what kind of festival or show it is you are going to but playing music is another way to draw people to your booth. you could get a vinyl banner made in bright colors to announce "sale" or something like that. people always like to think they are getting a great deal. i wouldn't give anything away for free unless it's with a purchase..i hope you make lots of money!