The other day I ran across this formula for creating patina on copper sheets with Miracle-Gro and vinegar and thought it would be worth a try. Hint - it has to be the Miracle-Gro water soluble azalea, camellia and rhododendrons plant food. You can read the directions here from Home Depot.
I would use copper sheets from a jewelry supply shop, Ace Hardware or Hobby Lobby - they don't have a coat and you'd like to use thicker .016 copper sheets for most jewelry projects.
(Photo credit: Home Depot)
This is a super fun idea from Rena Klingenberg using a Sharpie as a resist for patina - so many possibilities! Check it out here.
(Photo credit: Rena Klingenberg)
You can totally fake a patina with Vintaj's Patina paints. Check out the video on Lima Beads here.
(Photo credit: Lima Beads)
Have fun exploring coloring metal with these simple techniques! And if you try out that Miracle-Gro formula let me know - I'd love to see the results.