How to make an origami hat - origami snapback (Henry Phạm)
How to make an eight-pointed origami crown (http://www.origami-make.org/origami-crown-eight-pointed.php)
Pirate Hat Guide, from wikiHow
How to make an origami sun hat (http://www.origami-make.org/origami-hat-sun.php)
Origami Party Hat. use different sized paper to get different sized hats. You will also want to use a little glue to hold things together.
Useful how to make an origami hat - http://www.ikuzoorigami.com/useful-how-to-make-an-origami-hat/
Christmas Origami: Santa Hat
Newspaper hats, or boats.
origami+images+with+instructions | Origami Instruction: A Samurai Hat