Michelle Verbeeck has some beautiful examples of leather jewelry at her customleatherjewelry.com website.
Mary Jane first showed me leather bezels like this one from aosLeather on Etsy. We're going to try it with cloisonné if I ever get a piece sent to her (Sorry Mary Jane for being a slow poke!)
Melinda Orr whose talent and eye for design is amazing also uses leather to advantage as you can see here:
There aren't many left it seems...but if you are lucky enough to live near a Tandy Leather store...stop in. The variety of leather styles, colors, textures is amazing. I won't get into the "correctness" of using leather. It's not for everyone obviously. But we can all admire beauty, no matter it's form.