Step 10: Helmet, part 2
The distinct triangular Vader-cheeks were added to the face section later on when I realized it just wasn't very Vader-like without them.
I found that craft foam is really fun to work with in situations like this because it is flexible and will stay where you put it if you use the right glue. I used 3M 77 to attach it to the cardboard structure of the face section, and used wood filler to cover the seams. It has to be sealed well with decoupage glaze, however, before you paint it.