Men have it pretty easy when it comes to wedding attire: If the invitation says black tie, a tuxedo is in order, whether you own one or not. If you’re in the latter category, you must rent one. But don’t let the young guys at the tux shop rent you anything but the most traditional of tuxedos. In addition, instead of patent leather shoes that look like plastic, I recommend you wear a highly shined pair of black, lace-up dress shoes.

Proper attire for 95 percent of the weddings you will attend in your lifetime is a dark suit, dress shirt and tie. A suit means the jacket and trousers must match. If you do not wish to purchase one, you must send your regrets to the invitation.

A suit has a set of corresponding items that go along with it. First, a dress shirt—long-sleeved with a pointed collar. (Button-down collar shirts are not dress shirts.) Proper dress shirts are sold by neck and sleeve size and come in many colors and patterns. While white is a definite preference, a number of subtle pastels and a few discrete stripes also are fine. Do not wear a black-on-dark-purple shirt—in fact, I think the term 'dark dress shirt' is an oxymoron.

A neck tie is something every man should know how to tie by the time he is 12 years old. I’ll be forever grateful to the uniforms I wore in grade school. Once you’re taught how to tie a half-Windsor by a 6-foot-tall nun, you never forget.

The tie should be in a subtle pattern or solid color combination (never wear solid black to a wedding). The best look for a tie is a nice, tight knot with a dimple. The finished look should be triangular in shape, with the knot below the triangle as tight as possible. The tie should go to the top of your belt, and the back part of the tie is slipped into the label sewn on the front part of the tie. A sloppy knot—or a tie that is too long or short—must be retied. A dimple is acquired by the most dexterous of men. When slipping the tie into the knot, your index finger should hold the dimple in place as you use your thumb and middle finger to slide it into place.

Socks should always match your trousers, and the shoes should match your suit. I have always worn black shoes with black, gray and navy suits. In the latest men’s magazines, you often see brown shoes with gray suits. I still prefer black.

A suit is a wise and major investment, with a good, quality tailored suit from a fine shop running between $1,500 and $2,500. There also is a new trend for suit separates out there. This is where you buy the jacket in your usual size (no alterations needed), and the same-fabric trousers. This is an appropriate substitution for a ‘good’ suit and, if worn with a nice shirt, tie, belt, socks and shoes, looks fine.

Men’s magazines have decided that trousers on suits have flat fronts and no cuffs. That’s a shame, as I happen to like both. Another ‘new’ and somewhat disturbing trend is what I call a ‘Ryan Seacrest suit,’ suits that have a definite waist and a very tight, close cut. I hope this trend passes quickly, as this looks good only on young men with very thin waists.

Why not a sports coat? A sports coat is worn to the office, to the theater or to dinner. The very name gives it away: Is the bride wearing a ‘sports’ wedding dress or the groom a ‘sports’ tuxedo? Of course not. You, as a guest, have a responsibility to dress as nicely as possible for the couple’s big day.

A very few exceptions exist. There is a butler—a hopsack coat, usually with gold buttons. This can be worn with gray flannel trousers, or if it’s summer, white or dress khaki trousers. Poplin suits and seer-sucker suits may be worn to summer daytime weddings.

There are a lot of details regarding suits that you will pick up from the older men who shop at your suit store of choice, things like why the bottom button of any suit or blazer is left unbuttoned. There also is a matter of a full-break, half-break or no break on the length. For instance, a full-break is where the back of the trouser is long as the back of the shoe, and the front is long enough to have a few creases across the top of the shoe. Most men do not ask for help when buying a suit or tie, or a dress shirt. This is one occasion where I say trust your salesperson. Or, bring someone whose taste you admire and have them help you with selections.

Still wondering why we never button the bottom button? This tradition goes back to England toward the end of the Victorian era. The oldest son of Victoria, Edward (later Edward VII), was a large, corpulent man. He was unable to fasten the last button on his suits, jackets and waistcoats; so out of respect, his entire court followed. The practice then spread across the country and around the world. If you’re thinking, Oh, that’s stupid or I’ll not do that, you’ll get this answer—something you’ll hear a lot in menswear—Well, that’s just the way it’s done.

But take heart because someday, you’ll be able to say to some younger man, Well, that’s just the way it’s done.

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