The bottom layer is insul-brite, and that is covered by ironing board fabric. I stapled those layers on the underside. All the tutorials show stapling the cover fabric as well, but I wanted it to be removable for washing (or changing my mind on fabric colors). I cut a rectangle, and stitched a pocket all the way around. Originally I wanted elastic, but didn't make it quite big enough for that. I found some kitchen twine and put that into my pocket as a drawstring and it worked like a charm. I got a mini iron perfect for the tray table and use it to press seams as I go.
There aren't photos step by step on this one, but my husband wants a cover for his table so I'll do tutorial photos with that one.