The purse started out as a simple octagon --
The points don't show well, but there are 8 of them.
I kept going in a coil, working 1 round with increases and 1 round plain -- that way the piece would lay flat. And it got bigger:
At this point, it measures almost 20 inches from side to side.
The next step is to fold and sew the center inside seam, so it would be a tube like this:
The next step is to fold the bottom part up and make the gussets/handles.
To stitch the gusset, single crochet along the fold on the right side edge from the top to the bottom. At the bottom of the fold, chain 60 or so stitches (about 20 inches) for a handle, and then single crochet along the fold on the left side edge from the bottom to the top. Then chain the same number of stitches for the other handle. That finishes one round.
Do 3 more rounds along this base, working in (sc1, dc1) along the gusset and single crochet along the handles.
Then fold the piece up and stitch the gussets closed and slip stitch along the handles to make them into tubes.
I also slip stitched both layers together where the center seam is -- this made small interior pockets.
The next step is to rejoin the yarn at one top edge and double crochet a long flap in just plain rows back and forth.