I actually did these frames as a birthday present for a friend. You could get creative on what you use for the frame...a block of wood, old cabinet door, etc. I actually have a lot of old wood samples from a furniture company from my work that I used.
What you'll need:
Whatever you are going to use for the main part of the frame
(Cabinet door, block of wood, be creative)
Picture
Accessories to add on
(Metal pieces, appliques, etc.)
Glue
So on these wood samples, one had a lot of texture and the other a lot of wax which makes it kind of hard to glue anything on. I had to use a paint stripper to remove the finish from the raised panel in the center.
(If you are going to do this step have a clean surface that nothing can possibly be ruined if it drips our spills.)
Wear thick rubber gloves, if the stripper gets on your skin it will burn extremely bad. Pour the stripper into something you don't care about: an old bowl our cup. I used an old coffee pot I bought at the thrift store for a dollar for this very purpose. Use a paint brush and brush on the stripper. Let sit for about 30 mins. Use a paint scraper to scrape off the paint or finish. It may take a few applications to remove everything. Feel free to leave some for a rustic, antique look. When done clean with a damp cloth and let dry completely. I would use an old rag just in case it ruins it.
(Sorry I didn't get a picture of this)