I found the image below online to help me get the texture of the oxidation just right:
The picture below was take with a flash. Most of the time my flash pics do not turn out well, especially with shimmery or glittery nails but I like out the flash worked in this one!
So the base color I was going for was that of an old penny however, while Warm & Fozzie has great copper tones it doesn't have solid coverage being a micro glitter polish. One of my most recent polish purchases was Coco-a-go-go which is a shimmery brown with copper undertones. I swatched it and it worked perfectly with Warm & Fozzie to create the old penny color. After prepping my nails with a protective base coat, I applied one coat of Coco-a-go-go to each nail. After the polished dried, I applied a thin coat of Warm & Fozzie to each nail. Using a cosmetic sponge, I sponged on the tarnished spots with For Audrey and layered more with Savage and the unnamed Bon Bons shimmery blue. I also added Treasure Island's teal glitter and some iridescent glitter to add some sparkle. One final coat of Julep's Fast Drying Top Coat and taadaa! Tarnished Copper Nails!