Knitting, purling, cabling, decreasing, yarnovers, working in the round
I love cables, and for something like a cowl, reversible cables are especially wonderful, since they allow you to wear the cowl without worrying about the "wrong side" showing. The panels of openwork between the cables keep the cowl light and airy. It comes in two circumferences - the smaller circumference pictured, and a larger circumference, which allows you to wrap it twice around your neck for extra warmth. And for even more options, the instructions include information on how to work any circumference in between, to create your own fit and sizing.
26 sts = 3.5" (9 cm) in Reversible Cable and Openwork Pattern