The Windsor knot is perhaps the most widely used technique in tie knots. Pioneered by King Edward VII and popularized by his grandson, the Duke of Windsor, the knot has a couple of variations. You have your Full Windsor, also known as the Double Windsor. You also have your half-Windsor, but in this tutorial, we will stick with the refined Full version. The Winsor Knot is distinguished by its wide triangular shape.
Locate the seam that runs diagonally on the front of the tie. This serves as your starting point. With your collar flipped up, drape the tie around your neck so that the wider end is on the side of your dominant hand. Doing this allows you to tie a Windsor knot with ease. Bring the wide end of the tie over the seam of the thinner end.
Bring the wide end up through the triangle by looping it around completely around thinner end and let it hang down. The fat end should now hang over the thinner end. Next, bring the fat end back towards to the same side you just worked with. For righties, this would be the left side, and vice versa for lefties.
Swing Around to the Other Side
Bring the wider end around to the other side underneath the thin end. In doing so the front of the fat end should be facing you. You should be seeing the back of the tie as you bring it around. Again, the fat end should be behind the thinner end at this point. Right side for the right-handed, and left for left-handed.
Once you've brought the wider end to the other side, loop it around the thin end. Make sure the wide end comes back to that side, resulting in a full circle. For right-handed people, the front of the tie should be facing you on the right side. The idea of a Full Windsor is basically to wrap the wide end around both sides of the "V", resulting in two loops that mirror each other.
Bring the wide end to the other side by swinging it horizontally around the front of the knot. The front of the tie should now be facing away from you. Bring the wide end all the way around and to the backside of the knot. This horizontal wraparound creates a loop in the front.
Pull the wide end up and through the triangle so that the front of the tie is facing you and pointing upward. Next, thread the wide end through the loop you created in the previous step. It should come straight down and hang over the thinner end. The front of the tie should be facing away from you.
Pinching the knot with one hand, tighten the tie by tugging down on the thin end. The end product should be a wide triangular knot. Make the appropriate adjustments, if need be, to even out the triangle.