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
Alcohol Inked Tile Coasters - 25 Decorative DIY Coasters You'll Be Proud to Show off . SourceIf you look at the finished product, you would never guess that these are DIY coasters. All you need are some tiles, rubbing alcohol and alcohol ink!