Coffee beans are an excellent and intuitive choice for beads because of their size, shape and rich brown color. To string coffee beans for jewelry-making purposes, however, you first need to bore holes into them. This can be somewhat tricky, since the bean shells are hard yet brittle and easy to shatter. But if they are properly secured, you can easily bore holes into them with a power drill. The resulting beads are great for stringing on their own or pairing with beads of other natural fibers.
Pull a piece of polymer clay at least as large as the coffee bean you want to make into a bead. Soften it with your fingers, then press it onto the surface of the scrap wood, flattening it slightly with your fingers.
Press a coffee bean into the clay, positioning it so that the rough side is down and the smooth, rounded side is up. Roll your finger back and forth over the back of the bead while pressing to work it down into the clay and ensure that it sticks.
Set the drill to a low speed (if possible) and drill a hole through the back of the bean, positioning the drill so that the bit is inserted straight up and down rather than at an angle.
Turn off the drill and remove the bean bead from the clay. If any traces of polymer clay stick to it, wash them off using a wet paper towel and a little dish soap.
Repeat Steps 2 through 4 with all the beans you want to turn into beads.
Spread the beads on a sheet of wax paper and spray them with a coat of polyurethane finish. Let the first coat dry, stir up the beads, and spray again to get them fully covered. This will give them shine, make them more durable and eliminate the coffee odor from any jewelry made with them. Skip this step if you want your coffee jewelry to retain its smell and natural texture.