Folks love to win stuff
Anything to perk people up- it's great that you're doing this! I volunteer for lots of different events. Caps, visors, bandanas, cell phone cases, key chains, picture frames, candles &/or candle holders, any kind of grooming products, fly masks, coffee mugs and to go cups, water bottles or beverage holders/cozies, small soft coolers, any kind of gift card, coffees/teas/gourmet hot chocolate, candy/chocolate. It's nice too if you can find someone local who will donate something: a photo session, jewelry, blanket cleaning. Or try a volunteer type donation: one free day of stall cleaning for ex. Good luck & have fun!