How hard can it be?

My Crocus Bag is nearing completion.
In this picture, it’s about to be cast off.

As I’m knitting it in the round, and because of the structure of the stitch pattern, the beginning and the end of the round have the stitch pattern overlapping.

No matter how much I thought about it, I couldn’t conceptualise how to write the instructions.
I had to actually knit it to work it out. Even then I wasn’t sure how to write it. Doing a couple of repeats of the pattern, and jotting down what was happening during the second repeat, made it clear.

It’s amazing that the more familiar I became with the stitch pattern, the more mistakes I made and had to go back to repair.
I knew it so well, I’d relaxed into not concentrating so much. A fatal error.

Since this photo was taken, I’ve cast off, and am not sure how to finish it. It looked nice on the circular needles, gathering in at the top. Cast off, it seems a bit too wide open at the top. The possible ideas I have in mind are

• Folding the top over and threading a drawstring through.
• Weaving some fine elastic through the band to pull it in a little.
• Dunno
  

Once this is decided I’ll know whether straps are required, and think about what type would look good.