There are endless ways to knot your tie, but the quintessential knot, the 4 in hand, is the one we at Georgia Mae favor. Simple to tie, simple to untie, easy to slide and adjust - this knot looks clean and modern.
[See the illustration below] Drape your tie around your neck with both ends facing "front". Place the tail of the tie just above your navel. Bring the larger end of the tie across the tail (at about chest level), then behind, and then again across the front of the tail. Now bring the top up through the neck and drop the front down through the loop you created. Ensure that the tie did not twist - both the top and the tail should be facing front. You can adjust the position of the knot by gently pulling on the tail to raise the knot.
Whether you wear your knot neat or loose, high or low, your knot is a very personal thing. Take the time to knot and re-knot your tie. Play with it - slide it. Experiment and have fun!