I adapted a bought-from-the-store tote or shopping bag. I added some straps (hidden from the camera) to attach it to the bike. I am developing, and in the process of writing right now, sewing patterns & instructions on how to make or adapt your own bags. I will be offering these patterns (not the actual bags themselves) at my online store located at my Website series listed below coming very soon. It takes some time to not only write but to test the process to make sure it is as accurate and simple as possible for the home sewer. For that particular bag idea, I already completed the photos and most of the instructions. I have yet to make about 2 or so more bags and then they will be ready for offering online (I hope next month before the end-of-the-year holidays rush starts). I can assure you right now that I will keep the prices inexpensive just like a fabric store does.

Just keep coming back to this forum for further updates.