We finally got around to making valances for the bedroom. The hubby constructed the boxes out of foam insulation board. It's extremely lightweight so you can construct very large pieces that don't require massive hardware to hang. We just put two small L-shaped brackets and set the boxes on top.
We chose upholstery fabric as our covering and used Aleene's Fast Grab Tacky Glue to attach it to the foam board. For a little extra security I inserted some dressmaker pins at an angle on the interior fabric folds. We are pretty darned proud of our new window treatment.v