I have a few frames finished. For these, I used the Elmer's glue technique. First you paint your frame with any color that you want to show thru your top coat and let it dry. I used brown on one and black on the other two . Then apply a coat of Elmer's glue. Once it gets tacky, you put on your top layer of paint. I used white on all of mine but you can use any color. Always use your darker color to paint the frame. Just make sure and not go back and forth too much or the paint mixes with the glue and the effects aren't as good.
Very simple and you get a great look.