If you’re wearing a jacket (and you should) that has a breast pocket, that pocket should be filled to overflowing with a pocket “square”. The material of this object must only be cotton, linen, or silk. Polyester or any blend is forbidden because it looks cheesy.
Why wear one? Several reasons. The pocket square, like the tie, breaks up the monotony caused by draping one’s chest entirely in one fabric. Nobody now has the fortitude to wear a boutonniere, but these provide the same effect. The more the jacket angles towards one color and lack of pattern, the more the pocket square is needed. And if a jacket is loudly patterned, again, the pocket square can bring relief to the eye.
Ancient advice recommends a pocket square not be cut from the same bot as the tie. This advice is ancient because it is true. If the tie and pocket square match, the eye is strongly drawn to them, and you risk looking studied or goofy: worse, nobody will look at your face. Matching a pocket square to tie can be done, but the probability of a pleasing result is so low that it should not be attempted by the amateur.
There are four elements to wearing a pocket square: pattern, color, material, and folding. The pattern should usually be unlike the jacket entirely, especially if the color of the square is similar to the jacket. The more the colors of the jacket and pocket square are different, the more the patterns on both can match. If your jacket is loud, a simple white pocket square is best. But again, if you’re wearing a sharp, formal suit or dinner jacket, white is best. Pocket square patterns can be reminiscent of the tie, but should never match it. But neither should the pattern contrast too abruptly with the tie: don’t mix stripes and polka dots, for instance.
Simple colors are preferred. Shocking or bright hues draw the eye to them. Remember: the goal of a pocket square is similar to the visible half inch or less of shirt linen that peeps out the bottom of jacket sleeves. They both provide framing and relief. If your shirt linen stuck out several inches (or your jacket sleeves are cut too short), that is all people will see. One reason to dress well is to advertise yourself, not your clothes.
There are some obvious, but not strict, rules about material. If you should end up in a tuxedo, a white silk pocket square is the only real option. As with all clothes, the texture of the pocket square should angle toward the texture of the jacket. Sports jackets call out for cotton or linen. Wool wants silk.
Pocket squares are not cheap, and many men won’t buy them thinking that the cost of a piece of material whose only purpose is decorative is not worth the cost. Naturally, this forgets that occasionally a pocket square can be lent to a lady. As for cost, stick to simple white linen: it almost always works. Plus, you can make your own. For the past few years, cheap silk scarves from India and Pakistan have been sold in the States for as little as $5. I have taken these and cut pocket squares from them (one scarf will make a dozen). Similarly, old ties found in thrift shops can be pressed into service; but don’t use “rep” ties.
The more formal your dress, the less conspicuous your pocket square should be. If you’re testifying in front of Congress wearing a dark blue or black suit, the pocket square (preferably white) must be folded into a square, and no more than half an inch should peek out above the pocket. If you’re suit is still on the formal side, but not too severe, the method of folding so that the four tips of the linen show. When Fox television’s Brett Baier first took to wearing pocket squares, he would use this fold, but the tips stuck out so severely that you had the idea that if you touched one, you would cut yourself. The severity was all that was seen.
The younger you are, the less of your pocket square should show. If you’re in your twenties, you haven’t yet earned the right to be cavalier. Conversely, the older you, the freer you can be with showing silk. Once you’re past sixty, the pocket square can practically erupt from its home. This adds character. Of course, part of the reason this works is because when you’re older, your clothes are, too, and people expect a certain rumpled appearance.