1. Choose Your Fabric. Here in LA, we're big fans of F and S for upholstery weight fabric. Online try Purl or Sew Mama Sew. We love the dimple patterns that West Elm was featuring. Try ebay for inexpensive Kilim rugs/fabric to try something similar.
2. Measure twice and cut once. You will need two 24"x24" squares and four 13"x24" rectangles (leave an extra half inch for sewing on all sides).
3. Sew 3 sides (and add zipper). To be safe match up your fabric inside out and to make things durable, sew a double seam and decide where you want to install your zipper (so that you can wash this baby occasionally).
4. Repeat step 2 for your inner bag. Using a rugged muslin or other cheap, durable fabric, sew your inner pouch to the same measurements as the outer one but make sure to fill it with bean bag filler before your sew that last seam. You can either buy bean bag beans or you can use one of these alternatives.
5. Finish. Stuff that inner bag into your outer sleeve and zip it up. You're all done!
Check out In Search of a Bean Bag Chair that Doesn't Suck for modern version for sale in stores now.
(Image: West Elm)