As a final instalment to my report on after-sales service at Ralph Lauren, I thought it would be useful to recount some of the tips and lessons that Jan Ellul, the in-house tailor at the flagship store, had to offer.

I had written in a previous posting that shoulders are the hardest thing to alter on the suit. This is partly true, according to Jan. The shoulders are certainly much harder to alter than the jacket waist, sleeves or chest. This is because those alterations usually just involve opening up the seam, taking in or letting out some material and sewing it up again.

To narrow the shoulders, the tailor must detach both arms, shorten the material across the shoulder, cut back the padding and re-attach. “A bit of a major operation,” in Jan’s words, and not something to be given to a novice tailor.

[Note: strictly speaking, altering the arm length can require the arms to be detached, but only if the suit has working buttonholes on the cuffs – one good reason not to have this otherwise pointless feature on your jacket.]

However, even harder than altering the shoulders is altering the top of the back – the material around your neck and the collar of the jacket. To do this, the collar of the jacket must be removed, the back re-cut in one delicate slice, and re-sewn. Costly and risky.

So when you’re trying on that ready-made suit in the mirror, make sure the collar fits well first. It should neither stand away from the collar of your shirt nor hug it so tightly that folds of stress form across the top of the jacket’s back. Then worry about the shoulders, and only later consider everything else.

On the subject of the shoulders, Jaan notes that the way to tell whether they fit right is to find the point where your shoulder muscle is at its widest and make sure the suit’s sleeve material just grazes it. There should be a smooth line between that point and the edge of the shoulder itself.

Often, it can be hard to tell whether a shoulder is too big. It’s easy to tell if it’s too small – the shoulder muscle is bulging against the sleeve. But it can be hard to tell if it’s too small as in any case there is always a clean, straight line down from the shoulder of the suit. Jaan’s tip is the answer – find the muscle and make sure it just touches.

Finally, I asked Jaan’s opinion on Kilgour’s cut-price bespoke – where suits are measured in the UK, put together by Kilgour-trained tailors in China and finished off here. Jan is a Savile Row-trained tailor and I expected him to be conservative about it, but no. “There’s nothing wrong with things made in China, if they’re made well,” he said.