One quick, easy way to make a dinosaur costume with craft foam is to start with a hooded sweatshirt or jumpsuit and attach foam details, such as horns, spikes, scales or claws. Craft foam, also called EVA foam, can easily be hot-glued to felt and other fabrics to make a speedy yet creative costume.
For a larger, more accurate and labor-intensive dinosaur costume, start with a drawing of the finished costume. Use the drawing to create a pattern, keeping in mind that craft foam usually comes in small sheets, and may need to be layered and affixed to a sturdy fabric or cardboard base. To make a larger dinosaur without having to build an additional structure from scratch, build on top of basic items of clothing such as baseball caps, sweatshirts or backpacks.
Referring to the designed pattern, use scissors or a razor knife to cut the foam sheets into the desired shapes. Use hot glue to stick the foam pieces together and attach them to the base layer. Personalize the dinosaur costume by painting the craft foam to create a unique dinosaur skin texture. Add buttons, sequins, felt or other fabrics to build up a more realistic texture, or leave the craft foam unaltered for a smoother and more cartoon-like appearance.