And here is my overused homemade pattern, below, with a second photo showing what the folded fabric you’ll cut looks like when opened. The bottom edge is placed on the fold of the fabric, as you’ll see next….
I’ve cut the inner and outer shells first, then cut quilted cotton to use as an interfacing. Above the cut-out rectangles, notice that each side flap is about a half-inch wider than half of what will become the bottom of the bag–which allows for the side seams. (The length of each “B” = half the length of “A” plus a half-inch, as in the paper bag example.)
Use your pattern again to cut out the interior pocket lengths–quilted fabric can be added as interfacing, as in the following photo, but you could just double a sturdy fabric–such as canvas or duck, for use as interior pockets.
Next, I pin the pockets where I want to sew them, leaving an inch and a half below each pocket strip, so the pockets are near the bottom of the bag. Then I spaced and pinned the pockets on both sides about equally–with four pockets per side.
Sew around the entire pocket strip, turning the fabric and sewing up–and then back down–each of the individual pocket seams (I pause and add some extra stitching at the top, where the opening of the pocket might get heavier use), and then continue along the bottom until I get to the next pocket seam.
After the pockets are sewn on, place the (backside) edges of one side of the bag together, pin, and sew. Next, open the seams and tack down those seam edges.
Do the same to the other side, then flatten the bottom edges and sew those closed.
Using the remaining fabric, decide on the length of fabric straps. If you’re short on fabric, use the rectangular scrap fabric to make fabric tabs for four “d” rings, and buy handles at a craft shop. (I used scraps, and made a fabric tab to hold a brass ring in the finished bag photo.)
By the way, I cut the quilted interfacing for the handle straps short on both ends–it makes it easier to sew the finished straps into three layers of fabric–plus trim!
Next, sew the interfacing all around the outer shell (this step can be done to either the inner or outer shell), and then pin and sew sides as before, with seams facing inside and tacked down. Sew the bottom edges together next. At this point, I turned over and tacked down the top edges, pinned piping trim and handles on (centered, about six inches strap-to-strap on either side).
Sew it all down–it’ll make it easier to handle once you join the inner and outer shells.
Insert the inner shell into the outer, and find the bottom corners, fitting tightly together and pinning, then sew them down before moving on, to fit and pin the top of the bag. Before sewing the tops together, add any extras–like a key tag. Then sew around the top several times. Use a pattern or simply follow previous seams, but do get right to the top under the trim at least once, so the inner and outer bag edges meet well.
Last, a stabilizing bottom pad can really help. For this bag, I’ve cut out the same interior fabric, folded it to the size of the interior of the bottom, sewn it–leaving an opening–and inserted a cut-to-size piece of styrofoam. (I got the end of a roll from a pool supply company for this purpose, but you can use any stiff, recycled material that will hold its shape and stand up to hand washing. I’ve used cut, stained, and varnished veneer hardwood in the past, and skipped the fabric cover.) In this case, I slipped the styrofoam in its pouch, sewed down the edges all around, and then sewed a tacking cross in the center of the finished support.
Total time: about six to eight hours.