As part of a digital craftmanship course aimed at learning to use digital machinery such as laser cutters and embroidery machines, Veerle Heijnen, Chinouk de Miranda and Emmie Knoester were tasked with designing and producing an almost no-sew bag that could be folded from a single piece of fabric.
Taking inspiration from the design of an origami desk tidy; they laser etched the fold lines into some sturdy fabric, and embroidered a pattern onto certain parts for structure and decoration. They then folded the bag into shape, sewed on the strap and added magnets for the closure.
Head over the complete Instructable, where they have provided all of the files if you want to have a go at making your own. There are plenty of great fabric options to try out, just make sure that you aren't using anything vinyl based - they're very dangerous for you and your laser cutter! You could perhaps modify it to be completely no-sew by cutting slots in the fabric to thread a strap through, or maybe attaching them with rivets; or even add stitch holes to aid in hand-sewing.