When sewing a bag, the first question is always: What do I want to use it for? If it’s a simple shopping bag, it doesn’t require much effort—all you need is a sturdy fabric that can hold some weight and withstand wear and tear, along with good carrying straps or handles. If you’re aiming for something fancier, “easy” and “simple” are no longer options, because the more elaborate the design, the more work goes into making such a bag.
Picture 1 shows a simple bag that didn’t take much effort to sew—a basic little shopping bag made from upholstery fabric about 21 years ago; it hasn’t been around for a long time now. It involves sewing two side seams and attaching the bottom—with a little practice, it works out just fine.
You don’t necessarily need a pattern to make a bag, at least not for something this simple.

It’s a different story, though, if you want to sew a bag like this—a pattern is absolutely necessary. I sewed this bag for myself a few years ago, and as soon as my oldest granddaughter arrived, it was gone :-))

And a bag like this takes a lot of effort and time—it came in four sizes; this is the travel bag version, but I sewed all four sizes for myself back then. A pattern is absolutely necessary here.

Simple shopping bags don’t require a pattern—just a measuring tape and a little creativity. After all, you should know how big you want them to be and what you can carry. Basically, it’s just two seams on the sides, a hem at the top, and the handles—a bag that, with a little practice, should be sewn in a few minutes

Unless you embroider them first— ;-) :-)
Love, Inge