I've actually used this "Tertiary Masking" technique in my previous Valentine"s Card. Some of my blog readers had requested to see this technique again in my layout. Therefore I've used this technique again in my layout titled "My Cute Valentine".
I've cut out a huge frame and use some temporary adhesive to attach the frame to the background. Then I've used the center portion of the frame as the masking template. I've move it around the frame to do the masking. This will create the illusion of frames or layers within the huge frame. I've used some distress ink to do the masking here.