One wedding, no suit: rent, buy off the rack and alter, or is made-to-measure ever the sensible answer?

At once or twice a year, buy off the rack and pay a tailor. And the thing that makes that advice actionable is knowing what a tailor can and cannot change, because that decides what you are shopping for.

Cheap and easy: trouser length and taper, sleeve length, taking in the waist of the jacket, taking in the seat and thighs. These are routine and transform how a suit looks.

Possible but real money: jacket length, narrowing the shoulders, reshaping the chest. Some of these are close to rebuilding the jacket.

Effectively impossible: making the shoulders wider, and changing the chest by much.

So the rule when you try things on: the shoulders and the chest decide the suit, everything else is adjustable. The shoulder seam should sit where your shoulder actually ends, and the jacket should close without pulling. Ignore the sleeves being too long and the trousers pooling on the floor - that is the tailor's job and it is cheap.

Budget for the alterations as part of the price from the start, not as a surprise afterwards. A mid-price suit that fits your shoulders plus alterations beats an expensive one that does not, every time and by a wide margin. That is the entire secret and it is why the advice is so consistent.

Two months is comfortable time. Two weeks would not be.

I rented twice before buying, so here is what "looks rented" actually means, because it is not snobbery and it is not mysterious.

It is fit, and specifically it is that a rental is sized rather than fitted. You get the nearest size in stock, minor alterations at best, and the fabric is chosen to survive dry cleaning many times, which tends to mean it hangs slightly stiffly and photographs a little flat. In a photo the giveaways are the shoulders sitting wide and the jacket collar standing away from the neck, and once you have noticed that you cannot stop noticing it.

Where renting genuinely wins:

• Black tie, or anything you will wear once ever
• A dress code you would not otherwise own anything for
• Very short notice
• Your size is changing

For an ordinary suit you will need again in eight months, it is the worse deal both financially and in how you look. Two rentals is often most of the price of a suit you keep.

One thing I would say for renting: if you go that way, book the fitting early and be willing to say the shoulders are wrong and ask for a different one. The staff expect it. Most bad rental fits are people being polite in the shop.

On made-to-measure, and why the price being close to good off-the-rack should indeed make you suspicious.

Made-to-measure usually means a standard block adjusted to your measurements, a real improvement if you are an unusual shape, and largely wasted if you are close to a standard size, because a tailor can achieve the same result on an off-the-rack suit for less. At the cheap end the adjustments are limited and the fabric and construction are where the money was saved, and you can end up with a worse garment that fits slightly better.

It starts making sense if you are hard to fit off the rack: long or short in the body, a big difference between chest and waist, sloping or uneven shoulders. Those are exactly the cases where alterations run into the "effectively impossible" list above.

For a first suit worn twice a year, I would spend the extra on fabric and a tailor rather than on measurement. Practical version: mid-grey or navy, plain, wool, nothing shiny, and a weight you can wear in more than one season. That suit works for a wedding, an interview and a funeral, which is exactly the life you described. Avoid black - it is the one people buy first and the one that only really works for funerals.