Allison Coulson shares a tutorial at The Sewing Loft showing how to make a rockabilly style headband. It ties in a knot, with wires in the ends so you can shape them how you like. You can make also make a shorter version to wrap around a bun. Go to The Sewing Loft to get her tutorial.
[photo from Allison Coulson on The Sewing Loft]