There isn't really a pattern for this bag. It's essentially 22 garter stripe squares, seamed together in a very clever way. You can see the layout of the squares to form a bag on Ishi's Ravelry Project Page (it's her design).
I made mine from Briggs & Little Heritage 100% wool in Light Gray and Dark Gray. I used about 3/4 of a skien of the light, and a full skien plus a little bit of a 2nd skien of the dark (for the straps).
My squares, I CO 17 sts on size 8 needles and made 17 stripes/garter ridges (34 rows, with the CO and BO considered rows). I added 2 rows of crochet along the opening edge to give it more definition. To add the straps, I picked up and knit a 6 stitch I-Cord.
I added the fabric lining (serious on the outside, a party on the inside! LOL), machine sewed together/seamed and then hand stitched into the bag. There's a hidden magnetic clasp behind the lining to keep the bag closed (otherwise I found it sagged open a bit).
I don't have a hot water hook up in my washer, so I felted it by hand in my kitchen sink. It felted up well, but didn't shrink enough for my taste... so I stuck it in the dryer while still damp and prayed LOL It worked, though. After about 15 minutes it had shrunk to the perfect size and was dry, to boot!