Dragon Age Inquisition hasn’t been released yet, but fans are so excited they’re already creating props. Instructables user Steven K. Smith is a prop maker and he goes through all the steps of making the helmet from reference pictures to the final touches. He started with the only four images available of the helmet and built a base structure of styrene. Then it was time for clay:
I like to use “Monster Clay” for my builds. It’s easy to work with and will not mess with your silicone mold later on.
Basically at room temp it is fairly hard (great for detailing). A heat source must be used to make it malleable. I have a small convection oven in my shop that I use to melt down the Monster Clay. Once the clay is soft I started applying it in small clumps to rough out the basic shape of the dragons wings and the crest.