To avoid discoloration and blemishes in a polymer clay piece, don't touch the raw clay with your hands any more than absolutely necessary while sculpting. Sounds like an impossibility, but it can be done.

Wrap the piece upon which you're working in plastic film, and only uncover the part being detailed. This keeps a plastic barrier between your hands, which contain skin oils that show up as dirty streaks on the clay surface, and the clay itself. Constantly check the surface for tiny specks of lint or dirt which may have drifted onto the clay, and if you find any, get rid of them immediately. If you don't, they'll lodge themselves into the clay and create blemish headaches later.

Keep a package of baby wipes close by as you sculpt, and clean your hands and work area frequently.

Never leave an uncured polymer clay piece 'out in the open' and uncovered while you're not working on it. It will draw dust specks, pet hair, etc., like a magnet.

See Myra's work at Born Yesterday Dolls and in the ODACA Artist Directory.