I cut the bottom off the bags (and pulled off the handles that were on some) and then cut the bag into 3 pieces width ways. I then had 3 tubes and with a snip across, I had 3 strips from each bag.
I then made a base by basket weaving 5 strips one way and 5 strips the other way, then sewed the remaining 6 strips into loops which I lowered down over the other strips, continuing to basket weave to the top. The left over bits at the top I just folded under and stapled. Having never made a basket before, it was all a bit of trial and error and a lot of fun discovery. It's not particularly sturdy, but would work as a place to put all my reusable shopping bags.