I made this simple headband for my daughter to match the Miss Cosby Sweater I made her:http://www.ravelry.com/projects/LBK63/miss-cosby-sweater-2

Note: I crochet on the loose side, so tighter crocheters may need to start with a bigger hook or more chains.

Begin with a chain 55 (or length desired for the circumference of your headband), join chain with a slip stitch and chain 2 (counts as stitch), Herringbone double crochet (HBdc) in each stitch around and join to chain 2 with a slip stitch. Repeat around until you have 6 rounds. Crochet one round of single crochet and fasten off leaving a tail long enough to weave through headband to make the cinch. Then fasten off and weave in ends.

You could wear the headband as is or add an accessory to the cinch.

There is a tutorial for the Herringbone double crochet (HBdc) here: http://www.mooglyblog.com/herringbone-double-crochet-hbdc/