Enya headband is a relatively simple pattern, worked bottom-up and seamed. You can also avoid the seam by working a provisional cast-on and working a three-needle-bind off to join.
The size written is standard women’s but can easily be adjusted by working more/fewer pattern repeats.

The instructions are given both as charted and written.
I used worsted-weight wool for this piece by cascade yarns and 4mm/US6 needles.

The width of the headband is approx. 10cm/4”.