Step 1: Cardboard box
How tall you want it is up to you, I made it the size of my head and a half, after this cut strips about an inch or 2 apart. DO NOT go all the way through the cardboard except on the bottom and top tabs that will be used to glue the top and the visor.
Step 2: Make cylinder
Step 3: Make expansion
Step 4: Top part and visor
NOTE: Use the circle and trace the pattern on the cloth that will be used to cover the hat, do the same with the visor, but trace it twice, one for the top part and one for the bottom. You should do this now because it will be very hard to do this once the hat is assembled.