This is an ideal first cable project for a novice or a quick knit for an intermediate. There is only one "proper" cable with the borders in a much quicker cheat's "cable" of eyelet-rib.
The headband can be made to fit any size of head - instructions are given. This also allows you adjust how stretched you would like your cables to appear when worn.
The easy (quicker) option is to make the headband flat and then seam it since the seam will be hidden at the back. Alternatively, a more advanced knitter can make a seamless version with a grafted join.
Any good quality 4ply/fingering yarn could be substituted. A solid or semi-solid shade with good stitch definition is best, otherwise your hard work making lovely textures will be difficult to see.
S/M to fit 48-53cm/19-21" head
M/L to fit 53-58cm/21-23" head
Instructions given to adjust size for custom fit.
* MillaMia Naturally Soft Merino 100% wool, 125m/137yds per 50g ball, 1 ball Grass or colour