This one:
https://www.shopmartingale.com/image...uarter-bag.pdf
Step 6. How on earth did you get the elastic threaded down through the casing? I gave up and ripped out the stitches of the seam next to each end of the elastic. What am I'm not seeing in that step that makes it work? I left the 8 inch opening at the bottom of the short side. That didn't help with threading the elastic at all, just got it to the opening at one end of the casing. The bag is made and now in the wash (dropped one end of the handles in my cup of coffee) but I doubt I make another one unless I can figure out what I'm doing wrong. I was so frustrated.