No matter what you think of Slipknot's music, you gotta admit they have a cool, horror movie look. This video will walk you through how to make your own Slipknot full head masks. You'll be surprised how simple the process is.
An old shirt
Masking tape or duct tape
1. Blow a balloon to the same size as your head.
2. Put the shirt over the balloon.
3. Cut off excess parts of the shirt, like the sleeves. Now start to encase the shirt in the tape, with none of the tape touching the balloon.
4. Pop the balloon and remove it, cut out the eyes and mouth from the tape mask, and paint!