Instructables user 1truedrum is a huge fan of Star Wars so he was excited when his 7-year-old son asked to be a Tusken Raider for Halloween this year. He made every piece of the costume from scratch from head to gaffi stick. He used half inch plastazote foam for the helmet and built the helmet from wedges:
I started by creating half a sphere comprised of 8 wedges. To calculate a sphere multiply the diameter by pi (3.14) and divide by 8. This will give you the width of each of the 8 wedges.
Once sized and cut, I shaped the wedges using a heat gun. The wedges were glued with spray adhesive. A strip was added down the middle to change the shape from sphere to a more oval skull shape.
I then added a extension to created the depth of the head.
The front panel was added and tweaks were made to finalize the shape. Openings for eyes were cut along with the mouth and blood spitter. The muzzle was added and later shortened, lengthened and then shortened again.
He also used plastazote foam for the gaffi stick. He constructed the shaft and head separately and attached them together with a dowel rod and hot glue. He also inserted a steel bar to the shaft to keep it from bending. He used Sintra for the fins. He sealed the foam with FlexBond before painting it with acrylics.
Read more about making a Tusken Raider costume at Instructables.