I made one using a $10.00 oak TV tray. I covered it with 2 layers of thick cotton batting then a layer of cotton duck fabric. All this was shaped and stapled to the underside with a strong staple gun. Oak is hard and we had to finish tapping some of the staples in with a hammer. I then took 2 layers of muslin and cut it the shape of the tray and sewed elastic all the way around and took darts in the corners to make a removable cover to wash. I use Best Press on the seams as I piece so the top needs washed regularly.