In this case it's steampunk hats.
All you need is
- A cardboard pizza box, and a thicker piece of cardboard for the top part of the hat
- Lots of good glue
- Two different fabrics
- Steel wire
- A lot of crap to make it beautiful
Cut the cardboard pices and glue the fabric to the cardboard. Make a wire brim-line by spiraling the steel wire around the edge. Glue, glue and glue some more so it all comes together as a hat.
My favorite glue to use on this is contact adhesive, it stinks but the result is longer hold power. Then I use superglue for small details.
I recommend not to use hot melt glue, that will only work temporarily, after a while the hat will fall apart.
When the hat is glued together it's time to jazz it up. That's the funest part, you just have to open your eyes and look for random stuff that looks kind of steampunkish.
Everything from old jewerly to feathers to old watches.