1. Cardboard spirals are great for cardboard wigs, antennas, or scary egg carton eyeballs that fall out of your glasses.
2. Egg cartons and crates make great bumps, horns, tentacles and nostrils for animal costumes.
3. Braided cardboard, Rapunzel or Boy George are just a few options to get you started.
4. Picket fences can create bones, gladiator bracelets, etc.
5. Corrugated strands separated reveal those cool crimpy parts if you're trying to add new textures.
6. Fan folded cardboard holds it's shape well for bows, fins and wings.