Lay the scarf over your head, with one end a good six inches longer than the other.
Twist the longer end under your bun and wrap it around your head. The shorter end should be held taut over your shoulder and ear.
Take the hanging end and pull it back and over the bun, tying both ends together. Fan the ends out.
Alternative: Take the hanging end and pull it back and under the bun, tying both ends together.