Silver: Rub object gently with toothpaste on a soft cloth to avoid scratching. Rinse well with water.
Copper: Pour vinegar and salt over copper and rub.
Brass: Polish with Worcestershire sauce; or pour on ketchup, let sit, then wipe dry.
Chrome: Shine wet chrome fixtures by rubbing with newspaper; or rub with baby oil and a soft cloth. Test first on an inconspicuous area.