In reading this guide, you may think that the only end result is an identical Draugr helmet from the game Skyrim. In fact, there are many methods here which are useful for creating any sort of 3D shape from shoulder pauldrons to other game helmets.
Note that this process involves some potentially dangerous chemicals and tools, so if you're looking to replicate the things seen here than please exercise caution. A respirator is mandatory for almost all steps outside of the molding process, and in some instances gloves and safety glasses are a good thing to use as well. Be careful!
The methods that follow will furnish you with not only a replica helmet or armor, but also molds from which to produce copies for sale or outfit other friends in similar costumes. Moldmaking is somewhat tricky and expensive however, so if this is your first attempt at such an endeavor, I recommend starting with smaller pieces than a helmet first.
Onto the process!