I went to an all-boy's Catholic High School with a dress code. Although we didn't wear ties on a daily basis, they were required quite frequently. I learned how to tie a tie from my father at a young age, but I was always shocked by how many of my peers could not complete the simple task. There are many more fancy knots, but I always tie the four in hand knot. It does not make a perfectly symmetrical, massive knot, like the full or half windsor, but each knot has a unique charm. If you are in the market for a lovely tie, check out the Kiton Sevenfold (above) I have listed on eBay.
First, from Sette Neckwear:
Next from TM Lewin:
The ever important dimple @ GQ: