I'm an avid beachcomber so, I happened to have shells with holes in them already. I'm sure there's a way to poke holes into them but I have no idea how. You're going to need a few shells though (I used four).

You're also going to need nail polish. As many or as few colors as you like. But I love the new neon craze so I used some neon polish I had.

Grab your shells and just pick some portion and paint it with the nail polish. You'll probably need a few coats. You're aiming for paint dipped so try for straight lines and edges (a blob in the center isn't exactly paint dipped but feel free to try it).

Wrap it in wire or any other method you find suitable to attach jump rings and add a chain, ta da! Done!