I used the Fimo brand of polymer clay. I purchased it from Michaels on sale for $1.00 a pack. It is usually $1.99 a pack but a little goes a long way for scroll saw projects.
Polymer clay is a manmade material that remains pliable for long periods, but bakes or "cures" to hardness at fairly low temperatures. It can be sculpted, carved, stamped, textured, sanded, buffed, painted, and used to create sculpture, accessories, figurines, dolls, or jewelry, or to embellish other surfaces.
The process is very easy. In the case of the hand mirror I cut the project. The areas for the inlay are cut out and the clay is pushed into the voids. I try to get the surface of the clay fairly flat but it does not have to be perfect. The piece with the inlay goes into an oven at 265 degrees F for about 30 minutes.
After letting the piece cool for a while I use a belt sander to smooth the surface and make the inlay even with the top of the wood. Then sand to at least 400 grit to smooth the inlay. After I complete the project I coat the wood and inlay with lemon oil and spray with lacquer. I can think of many projects that could be embellished with this technique.
Wooden boxes, hand mirrors, Jewelry, crosses, the list is endless. If you mastered this technique I am sure you could do very well selling these projects because they would be unique.
One problem you might face is warping of the wood as it bakes. I found 1/4 inch wood warped too much but 1/2 inch worked fine.
Give this a try. It looks good and everyone will want to know how you did the inlay.