Once your polymer clay piece has been sanded, you'll want to buff it to give it some shine. (Unsanded clay can also be buffed, but for the very highest shine, sanding is preferable.)
Polymer clay can be buffed by hand with a piece of old, soft denim (white is best, as it can't possibly leave behind a trace of color), muslin, or other soft fabric. Vigorously rub the polymer clay against the fabric (or the fabric against the clay, whichever you prefer) until you achieve the desired results.
Hand-buffing produces a soft sheen. For the highest shine, power tools fitted with buffing wheels are your best option. You can use anything from a hand-held rotary tool (such as the Dremel tool), a bench grinder, or a jeweler's buffer. Some people even use rock tumblers to buff large numbers of beads with a minimum of effort. For more information on buffing with power tools, visit our page about buffing wheels.