Single-Breasted – Single-breasted jackets can have one, two or three buttons. In the first case, there is no doubt which button to fasten. In the second case, as is befitting for larger sizes and patterned fabrics, only the top button is done up. There was a time, in the Anglo-Saxon world and at sports events, when both buttons were fastened. In many old photos, the Duke of Windsor and Cary Grant can be seen with both buttons done up, but this has gone out of style. Jackets with the hard three button stance are those where the lapel rises from above the buttons. In this case the bottom button, which is usually at the height of the pockets, is not used, because it tends to pull the fabric and generally doesn't work well. Normally, only the middle button is used, but some people prefer to also fasten the first button. When the lapel, however, reaches down to the middle button, you only fasten this one. If you fasten the top button, the inside of the jacket is forced into an unnatural position resulting in unaesthetic stretching.
Double-Breasted – In jackets with four buttons, if the two upper buttons are further apart, they have a purely decorative function, and it is obvious the jacket can only be done up by the lower buttons, generally at the height of the pockets. This model leaves as much of the shirt as possible visible and was made fashionable by the Duke of Kent, who became George VI, as can be seen in the film “The King’s Speech”. There is also a four-button version with a soft, versatile lapel which can be buttoned using both top and bottom buttons. Jackets with six buttons can also have this versatile type of lapel and can be fastened by both the middle and the bottom buttons. Double-breasted jackets with six buttons are normally fastened only by the middle button, but there is a certain English school, of which the Prince of Wales is the most noted representative, where both the relevant buttons are fastened. In all of these examples, it is imperative to fasten the respective inside button, but it may be remembered that Aristotle Onassis, a great lover of double-breasted jackets, deliberately left it undone. In this way, the right-hand side tended to fall open, giving an impression of self-confident negligence which became famous and was imitated by others.
Turn-ups are said to have their origin, whether true fact or myth, in the habit of turning the trouser legs up to save them from becoming muddy. Until the 1930s, many men wore their trousers rolled up in a rather impromptu manner. Thus, the turn-up originated in the countryside where things were more relaxed and practicality prevailed over protocol. And for this reason, but not as a result of any arbitrary fashion rule, it is sometimes better to do without them. They are completely unacceptable with a tailcoat or morning suit, which are both older than the turn-up, but also with a modern dinner jacket, inasmuch as the fabrics and light leathers for evening wear are more adapted to red carpets and ball rooms, rather than muddy puddles. In general one can say that, after having been worn for a century, turn-ups are making a career for themselves. The thickness of turn-ups evokes a certain physicality which is very dominant in the masculine imagination, and they have become more popular in step with the fashion of going to the gym and, within certain limits, they are now rather the rule than the exception in men’s outfits. Therefore, there would have to be a special reason to not wear them. In general, turn-ups are appropriate or even necessary on trousers which ask for or allow natural colored or suede shoes. Wearing suede Oxford shoes with a pinstripe with no turn-ups is unthinkable. Suits are exclusively worn with black lace-ups, and the turn-ups should just touch the shoes if you want to demonstrate an assured feeling for style. In the end, it must be a matter of personal taste, but with an awareness, however, that formal suits and military-style trousers such as chinos are better without turn-ups. Trousers without turn-ups contribute to the severity of the look and this can be enhanced by doing away with the rear vents of the jacket, especially if double-breasted.