The half-Windsor knot, also known as the single Windsor knot, is a way of tying a necktie which produces a neat, triangular knot. It is larger than the four-in-hand knot and Pratt knot, but smaller than the Windsor knot. The half-Windsor is derived from the Windsor in that it is only brought up around the loop on one side rather than both. It works well with light- and medium-weight fabrics.
To tie the half-Windsor, place the tie around your neck and cross the broad end of the tie in front of the narrow end. Fold the broad end behind the narrow end and bring it forward on the opposite side. The left and right sides of the narrow end, and the inside of the loop around your neck, form a triangle. Continue folding the tie over the sides of this triangle, rotating around the triangle in one direction. The sixth fold should bring the broad end up over the top of the knot from behind; push the end down through the loop in front of the knot between the fourth and fifth folds, work out any wrinkles, and pull the knot tight. If the tie is unbalanced, untie the knot and try again giving yourself more or less length to work with.
The steps are: Start with the wide end of the tie on your right and extending a foot before the narrow end, Cross wide end over narrow and turn back underneath, Bring it up and turn it down through the loop, Pass the wide in from the front, from the left and to the right, Then, end up through the loop, and put it down through the knot in the front, tighten the knot carefully and draw it up to the collar.