One of the best mediums for creating recycled, handmade Halloween costumes is an old cardboard box. When my son was 5 years old, we went all-out cardboard for Halloween, constructing an indoor cardboard cave that took over 3/4 of our small apartment. I was a cardboard construction worker, my wife was a cardboard viking and after many hours of consultation and construction my son was a cardboard knight - for about 15 minutes. Once his friends arrived in their store-bought costumes he quickly succumbed to the idea that his handcrafted labor of love was inferior. Bummer. To save you this dismay I've outlined a few DIY cardboard box costumes that are fun to make and fun to wear, fully able to stand up to even the most caustic kiddie criticism.