I have made a number of different pouches. I wrapped the seams with bias tape (I like the look of flat seams and did not have to turn it inside out, which can be apain) and (for some) installed several zippers. I just sketched out what I wanted. I made them 15" square for the ones I used as project pouches. Sometimes I use a fabric back, and I like that look a lot. When I did a tutorial for my quilt guild, one of the ladies used window screen and it turned out well -- she did not want to have the pouch air tight.
They are fun and go fast. The sky's the limit for style -- make it the way that it is more useful to you. I use a little longer stitch and always stitched with fabric against the feed dogs so I did not have an issues stitching.
If I could find my materials. I would do a tutorial but right now, recovering from knee surgery with everything in boxes in the garage I don't know when I will find things
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