Tutorial: DIY Tissue Paper Pom-Poms this tutorial is pretty good. Use square sheets or tissue for a rounder Pom Pom. Tie the middle with ribbon and tied several on ribbon and hung them for a backdrop. Use thin tissue paper and fluff gently.
How to Make a Captain America Shield Cake with M&M’s, includes shield template
Captain America Cupcakes -- layered cupcakes inspired by Captain America's shield