The pattern is simple and well-written and I love the clever design. You can buy the pattern at Knit Motion by Amélie Bernier, and check out another similar headband pattern by Amélie for free here.
The only trouble I had was when I made the first curved part, I twisted the knitting for the second batch of stitches when picking them up. It doesn't make a real difference in the headband, but next time I will just pick up the stitches like the pattern says, RS facing!.
I also didn't really get the provisional cast-on. I followed this tutorial for using a crocheted chain as the base, but when I went to pull my crochet chain out, it didn't unravel and I had to pick out. I figured I just cast on with my needle in the wrong spot of the "hyphen" side, so I did the second piece the same way but with my needle casting on the other spot of that side. That didn't work either, so I had some more unraveling to do!
I thought I would have to learn the Three Needle Bind Off method for the seam, but it turns out I already know that one - as demonstrated by my MIL, although she could not remember the English name for the technique.