The Turtleneck

1
Drape scarf over shoulder, with one end significantly longer than the other end.

2
Loop the longer end around your neck three or four times in the same direction.

3
Tie a simple overhand knot with both ends of the scarf, and then tie another overhand knot to get rid of most excess fabric.

4
Fit the knot underneath the loop so that no excess fabric is showing.