I am looking everywhere for reusable materials these days, and I found my husband throwing away this giant bird seed bag, which was about to be used as a trash bag. Unfortunately (and fortunately), I made it into a tote bag so fast that I forgot to take a before picture. This took about an hour total, and that's with a break and a bobbin-winding. This is an easy project!
The material's a bit hard to work with - a kind of woven plastic, so I used my heavy duty needle in my sewing machine. I am certain it would bend a regular needle (beware, a bent or broken needle can kill your machine!).
Basically I cut the bottom off, then I cut about a 3-4" strip off the top and bottom (to keep the image somewhat centered) to use as the straps. I folded the strap material in on itself and stitched them first (as you can see, I did not hide my stitches!). Then I sewed the bottom straight. I also put a zig-zag stitch below the bottom seam to protect against fraying.
I've been skulking around several tote bag tutorials, but this one made the most sense to me in how to construct the box-bottom effect, seen here, from the inside. Basically you stitch perpendicular to the bottom seam, across the corners. It works like a charm, but the only problem is deciding where to draw the line. Where you sew that perpendicular bit determines how thick and deep your bag will be.
After I got the bottom together I hemmed around the top (you might want to do that bit first, because it will turn more freely in the machine without the bottom closed!), and then attached the handles. I plan to use this for groceries, so I want the handles to be sturdy, so I reinforced the stitching like this:
This was a quick and dirty, minimal measuring, sloppy first try. But really, it's not bad, and it will definitely do the job. It will easily carry a couple of large organic juice bottles and a couple of boxes of cereal (see the test run below). Of course I had to carry these around the house to test the bag! They did not fall out the bottom! Yay!