I used an 11.5 mm hook size, labeled “P”. I am sure that a loose stitch crocheter like myself could use a size 10 mm or a tighter stitch crocheter could use a size 12+mm.

There is an attached photo tutorial on how to make a reverse half double crochet edging.

If you have not used Curly Q yarn, it is a very stretchy yarn that can hide mistakes very well. I like it because it is fun and soft, and the choices of the color are pretty amazing too! My scarf came out to 46” long, not stretched out.

I also wrote up instructions for an adult sized headband, a child sized headband, and a scrunchie using this same kind of yarn, all of which I will post the free patterns for on Instructables.com, when I get the chance, soon!

I am selling the pattern for the scarf for $1.50 and please feel free to sell completed projects.
As always, thanks for looking!