You'll begin by taking one of the short ends of the scarf and tying it around your head from front to back.  The back should be underneath your hair at the nape of your neck.  The front should be at your forehead just at or right below the hairline.  Tie it there.

Bring one of the long sides over your head so that it goes past the center line.  You want to make sure the other long side will overlap it.

Then bring the other side up the same as before.  If it doesn't go far enough past the center then you may want to pin it in a couple of places.

Starting where your hair ends inside the scarf, twist the slack that is left.  You can either leave it slightly twisted for a more flat look to the headwrap or twist it alot to make it look like a band.  If you will do the latter, sometimes a length of ribbon or throwbeads give it a fancier look.

Bring the slack up and around the front of your head.

Keep wrapping it around and tighten it up to look neat.  You'll want to be lifting the "sack" part with your hair in it up and wrapping the "band" around.

When you reach the end, just tuck it into the top.  You can leave a bit of the end to make a sort of a flower shape if you'll be pinning it.

I hope you enjoy this design :)