Picture Frame Molding Diy . Diy wall paneling with picture frame molding. Divide leftover space by the number of picture frame boxes you want. DIY Picture Frame Molding Bless'er House from www.blesserhouse.com When buying lengths, keep in mind that material will be lost for corners.you will need more than you expect (based on sight alone). For example, starting on the main focal wall, we placed the. First, i took a long look at the wall to determine how many “frames” i wanted on the wall and how large they should be.