Find yourself an old wooden or metal picture frame. Make sure that the frame is a dark color, as shiny frames tend to reflect in the finished mirror. I prefer an oval or even better a round frame of about 12" in diameter. Don't get one too big; you will want to carry it around sooner or later. With very little effort these can be found for a couple of dollars at any second hand store, antique shop, or Goodwill Store. Flee markets, garage sales, and swap meets are a gold mine for these frames and I have bought beautiful ones for as little as .25 cents. Don't bother if the frame is a little beat up, you can always paint or refinish it, but be sure the glass is unscratched and clear. For a dollar or two glass can be replaced. I have also bought a round piece of glass and lead trim from a stained glass supply house and made some beautiful gifts from these. I have even trimmed them in stained glass. Total cost? About $20.00.
2. Buy a can of high gloss spray enamel paint. Read the label and make sure it is good for glass. Some paints are not. This can be found at any hobby shop, or hardware store.