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
*add this to build up baseboards in house - To make your baseboard more dramatic, add small pieces of trim to the top of existing baseboard, add a few inches and add another piece of moulding. Paint the wall and trim white.