Restore superficially scratched glass to crystal-clear condition by gently buffing the scratch in a circular motion with a cotton ball dabbed in metal polish. If you don't have metal polish on hand, head to the medicine cabinet for a bottle of clear nail polish and nail polish remover. Use the nail polish applicator to paint a layer of polish over the scratch, filling in the groove. After the polish has cured, apply nail polish remover to the glass to remove any excess polish. Voilà—your scratch has disappeared!