I loved this scene from the movie, Pirates of the Caribbean Stranger Tides. Didn't you?
Here's my inspirational photo:

Here is the way I would recreate the look if I was going to a Halloween party dressed as one of the mermaids.

I hope that this inspires you to create your own mermaid look
Thanks to my friend Sam for singing her version of the Jolly Sailor bold song.
She did an amazing job!