Always use the brown cardboard box side. These can usually be lifted from Hobo shelters. Black marker works best, but glitter can add a nice effect. Don't make your sign look too flashy, though, or they will think you used the money to buy a better sign. That sort of thing works in the business world, but not in this sector. Remember; you're a charity. Tell them you can give them a receipt for their tax deductible donation.
