Your appearance; whether sharp and confident, relaxed and cool, or sloppy and juvenile – is often reduced to the fit of your clothing. Finding the right tailor may be crucial, but there is nothing nearly as significant as sharing a critical eye with the fitting-room mirror.

Fortunately for most of us, picking the right fit doesn’t require much natural talent. All that’s required is some quality time with apparel and an attention to detail. The following serves as a general fit guide for the novice.

Preface

Before we jump in, let us note that clothes best flatter a fit body. When it comes to your appearance, apparel is only part of the equation. It is important to eat well, drink well, and exercise occasionally. Many of us have busy lives and we cannot all be models, but you don’t need six-pack abs to look good.

It is much easier for clothing to look great for someone in shape. However, losing weight isn’t the only thing that matters – if you’re lanky and stick-like, start working out. It will help you fill out your clothes.

Additionally, before beginning have someone accurately take all of your measurements. These are very useful numbers when shopping for clothing in-store, and they are absolutely crucial when shopping online.

Dress Shirts

The collar should just graze your neck without constricting it. If turning your head causes the collar to turn with it, the collar is too tight. You should be able to comfortably fit two fingers inside of your buttoned collar without it tightening against your skin.

Your cuffs should meet the point where your palm begins (about 2cm up from your wrist bone). It should be tight enough that your thumb notch at your wrist will stop the cuff from moving up your hand. It should be a bit looser than a properly fitting watch, and not go farther up your wrist than that watch.

The shoulder seam should be at your shoulder bone. This is the point on your shoulder that is the greatest distance away from your sternum.

Sleeves should not be so tight that you can see the details of your arms, but they should also not be so loose as to billow. When you bend your arm, your cuff should not move more than an inch up your wrist.

Shirt length should be such that bending and making natural movements does not cause the shirt to become untucked. Additionally, your shirt should remain tucked if you fold your hands behind your head. If this is a problem, the shirt may be too short or the armholes may be too low. Alternatively, armholes should not be tight around the shoulder.

Pictures:
Left: Just right, cuff stops where your palm meets your arm. 
Middle Left: Sleeves are to long and start to cover the hand.
Middle Right: Too large asize causing the shirt to billow and crease.
Right: Shirt is flush to the torso but loose enough not to restrict movement.

About 2 cm of shirt should be revealed by the jacket collar. The shoulder seam should lie on the edge of your shoulder. The aim is to reduce the amount of buckling, as the shoulders should have no apparent wrinkles or divots while the arms are down at the sides.

Similarly to shirts, armholes must be sufficiently high, and alternatively should not be cutting into your armpit. The arms should move somewhat independently of the jacket during normal motions.

While buttoned, the jacket should not pull across the chest (fabric making an ‘X’ shape across your abdomen). Similarly, it should not pull across the shoulders when arms are folded.

Holding your hand flat, you should easily be able to fit it inside the jacket under the lapels.

The jacket’s second button from the bottom should lie just above your belly-button, never below.

With your arms at your sides, the sleeves should cover the wrist bone.

If a jacket doesn’t fit your shape properly, sometimes the bottoms will flare out, a product of the jacket being too slim in the waist, so your hips push out the fabric.

A suit jacket’s length – like a good lawyer – should cover your ass

Pictures:
Left: Tell-tale X shape at button when a blazer is too tight
Middle Left: No folds of fabric bunching at the button; a perfect fit
Middle Right: An unsightly divot at the shoulder of the suit jacket.
Right: The shoulder is smooth with an uninterrupted line.

Coats

Most rules are the same as suit jackets, in that shoulder seams should lie at your shoulders (given what you’re wearing underneath).

Keep in mind what you will be wearing under your coat, as the size will need to adjust accordingly.

The coat should not be roomy, but should lie close to your body and accentuate your shape. That being said, it should be in no way taut, and should allow freedom of movement.

Sleeve should go about an inch up your hand from your wrist (an inch longer than a dress shirt sleeve), to ensure that you’re not showing any sleeve from something you’re wearing underneath.

Like a jacket, if a coat doesn’t fit right sometimes the bottoms will flare out like a bell, beware of this. It makes the coat look skirt-like.

Chinos & Dress Trousers

CHINOS
No pants should need a belt to stay on your hips.
The pants in the image are somewhat a slimmer cut. There is nothing wrong with the fit, but some may prefer a more conservative look.

Avoid pleats. They make you look as though you are carrying more weight around your stomach.

The chino should not be tight to the leg, but also should not billow. It should be comfortably close to the leg without causing resistance.You generally want a single break in the pant leg. A break is a crease at the base of the pant leg created when the pant collapses onto the shoe. If you’re going sockless with slim chinos then you probably want no breaks.

DRESS TROUSERS
Similar to the Chino in fit, dress trousers should not be tight to the leg, nor billowing but, lie comfortably close to the leg without resistance but they will naturally drape more.

Again, avoid pleats as they make you appear heavier.
The trousers should have a single defined crease down the center of each pant leg.

You want to aim for a smaller break, but you still want a break. Some people opt for a cuff that weighs down the pants and has no break, some even use lead sewn into the cuff to achieve this. I believe a small break (as shown) is pleasing to the eye, and Brooks Brothers adhere to this style.

Jeans

Regarding cut, the jeans should be slim in the thigh and straight or tapered from the knee down. Avoid bootcut.

Go with your waist size and stick with straight leg or slimmer. Size down 1 for a slimmer fit. The jeans will stretch.

When it comes to breaks due to gravity, most people don’t want more than a few, as shown. Some people aim for more breaks, this is called “stacking”. Ultimately the number of breaks is a matter of taste. Depending on the style of the jeans and rigidity of the denim, you can get away with bunching further up the leg. Since jeans are very versatile and can be fit with numerous styles, this varies.

Length can vary if you plan to cuff the jeans. Jean cuff can vary from 3-12cm depending on your style.

Ties

The tie should simply sit under your collar, and should not tighten your collar.

Your knot should vary depending on your collar. A wider collar, such as a cutaway, would call for a larger knot such as a full-windsor. A narrow collar, such as a pointed collar, would call for a four-in-hand. Experiment and see what knots look good to you.

While standing straight, the bottom of your tie should just reach the center of your belt

Shoes

While on your feet, you should not be able to easily fit a finger behind your heel (this varies a bit, but your shoes shouldn’t be roomy).

You should be able to barely graze the front of the shoe with your toes. The front of the shoe should not be pressing on your toes.

The shoe should exert little to no pressure on the sides of your feet. This should be obvious, but walking should be comfortable and take no effort.

With formal shoes choose a round-toe (as pictured) as flat-toed shoes give your foot a clunky appearance.