Unplug the lamp from the outlet before you begin any cleaning.
Determine which type of glass your lamp is made from. If you cannot determine this on your own, consult the user's manual or the manufacturer.
Clean lamp shades made with opaque stained glass, art glass or jade stone with a lemon oil-based furniture cleaner. Squeeze a dime-size amount of the furniture cleaner on a lint-free rag and rub the surface of the lamp gently. Wipe until the oil works itself into the surface of the lamp and dirt is removed.
Dust lamps made from mica gently with a lint-free cloth or feather duster.
Apply glass cleaner to a lint-free cloth and wipe the surface of the lamp gently if its made from beveled or clear glass.
According to the Tiffany Lamps Dealer website, you can mix 4 cups of warm water with 2 to 4 drops of dish detergent and apply it to a cloth to clean lithophane porcelain lamps. Hold the lamp firmly and apply the mixture gently with a soft cloth. Use scouring powder to clean non-colored portions of the lamp. Wipe the lamp with a dry lint-free cloth to remove water and finish cleaning.