Guys. You have it so good. Women's fashion is in constant flux - which is probably why we are always a little insane. But men's fashion is constant, reliable and adaptable. You have fundamentals that can be accessorized easily. What you need to know is minimal. It just takes a little practice.
Every jacket has a lapel; there are three types of lapels:
Notched (in American English)/Step Lapel or Step Collar (in British English) - this is the standard on Single-breasted suits and is used on nearly all jackets. It's sewn to the collar at an angle, creating a "step" effect. I like it for it's solid, masculine cut.
Peaked Lapel (American English)/Double-breasted style lapel or Pointed Lapel (British English) - the most formal. It's usually featured on Double-breasted jackets. This is not my favorite lapel but it looks good on Double-breasted jackets because it's so stylized.
Shawl Lapel, Rool Collar, or Shawl Collar - a simple continuous curve and is common on a dinner jacket (also called a tuxedo); they are rarely seen on other jackets. Most modern tuxedos have Peaked collars nowadays but the Shawl Lapel has a real sleek design.
It's important to take notice of your suit jacket's lining. The lining, or canvas, is a layer of sturdy fabric that prevents the wool of the jacket from stretching out of shape. Floating Canvas is the most expensive; Fused (or glued) Canvas is usually found in cheaply manufactured suits, it's less soft and is less durable. All bespoke suits have Floating Canvas. Most jackets have Canvas in either the same color as the jacket or a slightly lighter shade. You can find many jackets with wildly different colors in the Canvas; the splash of color is fun and can even be sharp looking.
Lapels have buttonholes on the left, intended to hold a boutonniere. The only time you'll need to put something in that buttonhole is when you're getting married or someone you know is getting married. So, don't sweat the small stuff.
The width of the lapel has varied over the years but nowadays fashion leans back to the narrower. (For more details on various lapel widths, see the section below on Trousers.)
Buttons of jacket cuffs are normally decorative; bespoke suits have functional buttons. All styles of suits have three to four buttons, though a modern twist is five buttons.
Waistcoats were almost always worn with suits prior to the 1940's. They are not very common now - though they do look pretty slick.
Also known as "slacks, they are made from the same fabric as the jacket. Trouser styles have varied over the years:
Throughout the 20's, 30's and 40's the pant leg was pretty wide.
By the 1950's and 60's the slim leg became popular.
And besides the slight hiccup that was the 1970's, the slim-legged trouser has remained popular.
Originally, no suit was worn with a belt, but wartime shortages on elastic contributed to their rise in popularity. Braces (or suspenders for all us Yanks!) are worn by attaching them to the outside of the waistband with buttons. Nowadays most braces are affixed by a button on the inside of the trouser. Most trousers are not cut with braces in mind and have to be altered for that.
It's easier to find a belt and most belts are sleek and fashionable. Braces are a nice, eccentric touch. You don't have to go super goofy and wear rainbow-smiley face suspenders. Plain black or darker colors are just fine.
Next Up: Neckties and Shoes