How To Tie A Tie/The Knots
Four basic knots exist for tying a tie: the Four-In-Hand, the Half-Windsor, the Windsor, and the Pratt knot.
The Windsor or Half-Windsor knots are more commonly used for interviews or other formal occasions. Their heftiness and symmetry will convey an air of confidence.
The Four-In-Hand are usually used in more casual scenarios.
Oriental or Small Knot
The most basic knot. It forms an asymmetric knot with a wider base than the Four-in-Hand. It is not worn very often, possibly because it is not self-releasing.
The Four-In-Hand is a basic knot worn frequently in the West. It is also the easiest and fastest knot to tie. The knot produced by this method is on the narrow side, slightly asymmetric, and appropriate for all occasions.
The Half Windsor is for situations of moderate formality. It is luxury without pretense. It requires a little bit more time and practice than the Four, but the results are worth it. It is considered a simpler version of the Windsor knot, and gives a neat, triangular knot. The size of this knot falls in between the four-in-hand and the Windsor knots. It works particularly well with lighter fabrics.
The Windsor knot is generally perceived as the most formal and "upper-class" of the necktie realm. It is sometimes referred to as a full Windsor, to distinguish it from the half-Windsor. It produces a wide triangular knot. The knot is named after the Duke of Windsor (Edward VIII after abdication), who preferred a wide knot and had his ties specially made with thicker cloth in order to produce a wider knot when tied with the conventional four in hand knot. In Ian Fleming's James Bond series, the British spy remarked that the Windsor knot was "the mark of a cad." Its broad loop and wide knot are unmistakable. However, wearers of the Windsor knot may be marked as arrogant, especially as the current fashion is for smaller knots.
Pratt / Shelby / Shelby-Pratt
The Pratt offers a good balance between simplicity and class. Once learned, it's quite easy to tie. For the Pratt knot, the starting position is 'reverse side out'. It uses less length than the Half Windsor or Windsor knots, and so is well suited to shorter ties. Unlike the Four in Hand knot, the Pratt method produces a symmetrical knot. It is of medium thickness. Its one disadvantage is that the tie occasionally comes a little loose around the neck with extended wear, but a simple tug is all that's needed to refresh it. It shapes itself naturally, requires almost no adjustment, forms its own dimples, and is very easy to learn.