This instructables is based off of Will's work from stormthecastle.com, or http://www.stormthecastle.com/how-to-make-a/spartan-helmet.htm
Check out his site and see more boss instructions!
Step 1: Template
I attached 3 easy pieces. Print out all of them, and cut them out. Cut two of the 1st one, the one that resembles the helmet most.
Sry, but no pic for this step, you'll kind of have to make sense of what you've got!
Step 2: Add a Balloon Dome
Pretty straight foreword, blow up a balloon inside the circular helmet, and tape it down
Step 3: Paper Mache! Yay!
This picture shows the helmet after three coats of paper mache. I applied one thick coat and let it dry overnight, I applied a second coat and once again let it dry overnight. I finally applied a third coat and let it dry. I recommend you do four coats if you want it to be durable.
You will notice, particularly with the first coat of paper mache that the shape of the helmet will distort a bit. You can use this to your advantage and get the shape of the helmet to look really good. The long curving sections at the bottom of the helmet are a good example of this.
Step 4: Finishing/painting
The only thing left, once it dries, is to paint it. I used cans of spray paint black and gold. I painted the whole thing in gold then spattered black for highlighting. For this, you could use acrylics, then use black to distress.