I was looking for some kind of "paper lace" that I read about in a book, and walking through a craft store I found the closest thing. Paper doilies for a tea party.
I cascaded it out like scales on a mermaid, pulling it out to give it some depth. Next time I might buy white dollies and paint it sea green and aqua marina to really go for a mermaid look.
I couldn't use a store bought party hat as a base because it was just too small, so I used some scrapbook paper (in this case from a 8 bit video game theme). It actually makes it pretty cool linning for the inside.
I used some ribbon instead of an elastic to let it stay on the head. Unfortunatly I used some cheap ribbon so it wasn't very comfortable (lesson learned). I also added some strings of pearls to make it more wild.