Start with the Shoulders, Not the Waist

Most of us try on a blazer and go straight for the waist, pinching the fabric to imagine what a tailor could do. That instinct is understandable, but it puts the emphasis in the wrong place. A good tailor can take in a waist, shorten a sleeve, move buttons and reshape a skirt. What they cannot easily do is rebuild the top of the jacket. The shoulders are the architecture of the garment, and once they are cut, they are more or less fixed.

This is the quiet heart of slow fashion: buying the jacket whose shoulders already fit, then paying a tailor to perfect everything else. Find the right shoulder first, and you will wear the blazer for a decade rather than a season.

Where the Shoulder Seam Should Sit

The shoulder seam should finish at the outer edge of your shoulder, roughly where the collarbone ends and the arm begins. Stand sideways to a mirror and look for a smooth line from the neck to the sleeve, with no ridge, dent or droop. Two common faults are worth knowing by name:

• Too narrow. The seam bites into the top of your arm, the sleevehead digs in, and horizontal creases appear across the back. Shoulders end up looking rounded and bulky.
• Too wide. The seam slips past the shoulder joint, leaving a hollow divot under the sleevehead and a sloping line. Counter-intuitively, this makes shoulders look smaller, not broader.

Structure matters as much as measurement. A slightly roped sleevehead, where the sleeve is set with a little lift and roll, adds presence and is a great friend to narrow or sloping shoulders. Soft, unstructured shoulders are wonderfully relaxed but offer less support, so they flatter an already-square frame rather than creating one.

Always test shoulders in motion. Reach forward, roll your arms, sit down. If the jacket rises up around your ears or the collar lifts away from your neck, the fit is wrong.

Lapel Width Is a Question of Proportion

Lapel width should relate to the width of your shoulders, your chest and even your face. A narrow lapel on a broad chest looks pinched and mean; an oversized lapel on a slim frame swallows the wearer. A useful rule of thumb is that the lapel should reach roughly halfway across the distance between your collar and the shoulder seam. On most people that lands somewhere between 8cm and 9.5cm, with peak lapels running a touch wider.

• Broad shoulders or chest: a wider lapel, around 9cm to 10cm, restores balance.
• Narrow or sloping shoulders: stay in the middle, and look for a higher gorge, the point where collar meets lapel.
• Longer face or torso: a wider lapel and slightly lower gorge fill the space.
• Shorter frame: a narrower lapel and higher gorge lift the eye upwards.

Peak lapels push the eye outwards, which is why they suit narrower shoulders so well; a notch lapel is quieter and better for everyday wear. Also check the collar itself. A collar that stands away from the neck is a common flaw and makes even good shoulders look sloped.

Button Stance Sets the Whole Balance

The button stance is simply the height of the top button, or of the single button on a one-button jacket. It decides where your waist appears to be, and it changes the entire silhouette more than most people realise.

• High stance: nips in high up, shortening the torso visually. It can look fussy on a long frame.
• Low stance: elongates the body and looks elegant, but on a short torso it drags the visual waist down towards the hips.
• Standard stance: the top button sits at or just above your natural waist. Find your waist by bending sideways; the crease is your guide.

On a two-button jacket, fasten the top button only. The lower one sits below the waist and gives the skirt something to work with. One-button jackets are more formal and the button should sit at your natural waist. If the front pulls into an X shape, the jacket is too tight. If it swings open like a curtain, the stance is wrong for you.

A Fitting-Room Checklist

Take your time, and wear the shirt and trousers you would normally pair with the jacket.

• Button up and check for X-shaped creases across the front.
• Run a finger under the shoulder seam; it should sit flush, not float.
• Inspect the back for a collar gap, vertical folds or pull across the shoulder blades.
• Lift your arms and reach forward; the jacket should stay put.
• Let 1cm to 1.5cm of shirt cuff show at the sleeve.
• Check the length falls around the curl of your hand or covers your seat.

Buying Fewer, and Letting a Tailor Finish the Job

Classic British style rewards patience. One well-chosen jacket in a mid-weight cloth, hopsack for summer and flannel or tweed for winter, will outlast three that almost fit. Budget for alterations as part of the price: taking in a waist or shortening sleeves is straightforward and inexpensive, and it is the difference between a garment you tolerate and one you reach for.

Anything at the shoulder, though, is where you stop. If the shoulders are wrong, put it back on the rail, however tempting the discount. Care for what you keep: brush it, air it overnight, rest it a day between wears, and dry clean sparingly. That is the real substance of slow fashion. The fit is what makes you return to the same jacket again and again, and a jacket that flatters your shoulders will always earn its place.