Have you ever tried altering cabinet cards? These are the sepia toned images you can find at the flea market, from around the 1850'5-1920's. You know, the ones where no one ever smiles. I can never figure that one out! Here is one of my book covers with an altered card.
You can see a set of my altered cards on my Flickr site here. The key is to mask the image, itself, then you are free to alter the background by sanding , painting, stenciling, rubberstamping, or anything you can think of. Once finished, add some rub-ons or phrases and these become pretty interesting little works of art! Try one!