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
Alice Fox tapestry weave with found object and rust - my note - I could see this as a way to display the beautiful rusty square nails that are little found treasures all over the islet from the silver mining days.