Patina--vinegar (white or apple cider) and salt. For small items, fill a quart yogurt container half full of vinegar, and sprinkle in about 1 tsp salt. Add any metal you want to 'age'. Seal if you touch items a lot
Door knobs are a great way to personalize your entry way to display your own unique sense of style. This weathered, vintage door knob would be a perfect match for a old world style or antique wood door.