Seriously. My hat took like an hour or so. It's really easy and looks good if it's done the right size. Here's a look.
All you need is:
-lots of pins (you know the straight pins that have a long flat top)
-4 hair combs (the kind that you put in your hair to make things stay
Cut the fabric to the right size, glue it, pin it, it's really not too hard. Adding the combs gets a little tricky but cosplayers are known for ingunuity. Just have a hot glue gun and lots of pins ready while making this. Half the fun in creating a costume is trying to figure out how to do what.
I can send you pictures of just the hat inside and out if you need.