Earlier this summer, I finally got around to using some vinyl fabric that I had bought at Joann's on clearance last year. I basically used this tutorial with just some minor adjustments. Instead of using my sewing machine, I serged the seams, which made the project go very quickly. I also used just two ties instead of three. Unfortunately, there was probably a reason why I got the fabric so cheap -- the seams are already starting to come apart a bit where the ties pull on them a bit. Now that I know how to make these, I will probably invest in some better fabric and make them again. And I may just skip adding the ties.
(Ignore the ugly old discount-store tablecloth -- it needs to be replaced, too.)