Part of my layering process, in the very beginning stages of making a painting, involves a smattering of embossing foils.
I tear the foils, then glue them down with a gel medium, and let them dry. Once dry, I peel off the clear layer, and love the way certain parts of the foil stay in place and others peel up into gorgeous organic shapes that emulate decay.
I know this isn't the way they are used in the printing industry, but that's part of knowing the "rules" of art, and then breaking them, right?