I did this project with my friends, and one friend- Hilary, suggested we marble different colours of polymer clay together. O.M.G. Most awesome idea. We used light blue, tan and neon pink, some plain leather cord ($1.50 at Len's Mills) and some jewelery making pieces (jump rings and lobster clasps).
Don't the marbled colours look so cool?!
From there I also did a couple other variations:
And a couple of rings, by just using ring blank (or bases- I always get mine off of eBay), square or rectangular polymer clay pieces and some E6000 to glue it down!