1. Start with the wide end of the tie on the right and the small end on the left. The tip of the small end should rest slightly above your belly-button (this will vary depending on your height and the length & thickness of your tie). Only move the active (wide) end.
2. Wide end over the small end to the left.
3. Under the small end and to the right.
4. Up to the center, towards neck loop.
5. Through the neck loop and to the left.
6. Across the front, over to the right.
7. Up into the neck loop from underneath.
8. Down through the loop you've just created in the front.
9. Tighten the knot by pulling down on the wide end. Slide the knot up & adjust.

Source: Ties.com