I've seen a lot of tutorials for grocery totes and bags and the like but I never found one that I thought was easy enough for someone like me to follow. There is an excellent one on Craftster that makes a t-shirt bag almost exactly like this one but it uses a very different technique for constructing the bag. This one may not end up as refined but I think it might be easier for some sewers to follow.
Step 1: Cut out your fabric
You can use an existing bag for the pattern. Just cut off the seams at the top of the handles and the bottom seam. Then cut up each side so you have a pattern to use that looks not unlike a wife-beater.
You need to cut four pieces of fabric total, two of the lining fabric and two of the outside fabric. I pulled some quilt fabric out of my stash to make this bag and I used two very different fabrics so the inside and outside would be easily distinguished.
The Debbie Mumm chicken fabric is for the outside of the bag. The black chicken wire print is the lining fabric
Step 2: Sew the sides
Pin the outside fabric right sides together and sew up the both sides. Do the same for the lining fabric.
Step 3: Press!
Open up the fabric and press the seams to one side. A note about pressing: Do it. And take your time about it. You'll brand yourself an amateurish noob if you neglect this. Precise pressing is the difference between something looking hand-crafted and something looking like it was homemade by a ten year old girl scout.