I' m looking for advice and or help in making cornice boards for my family room windows. The windows are about 48 inches wide and I'd like them 8-10 inches top to bottom and about 4 or 5 inches out from the window. Hope that makes sense. I don't know what to make the framework from. I thought of using foamcore and covering it with batting and fabric with maybe covered buttons to make it look more finished. I can't figure out how to fasten the side pieces to the front piece to make it sturdy and then how to fasten it to the window frame or wall. Any suggestions?