Host a Costume Swap Party! If your children are up for a ghoulish good time, throw a costume swap party prior to Ecoween. Invite tots of all ages over and ask them to bring their old Halloween getups. After picking numbers from a witch's hat, allow each wee one to select a "new-to-them" costume from another guest. This holiday exchange not only saves parents money, but the hassle of finding a new outfit.