DUSK was falling over the Scottish hills as a bugle played the last post. Caps in hand, members of the Boys’ Brigade summer camp stood sorrowfully around a newly-dug grave. Heads of state have been interred with less solemnity. In this instance, the shallow grave was occupied not by mortal remains but by a tatty, torn, begrimed pair of khaki shorts, erstwhile property of the BB company leader. Reluctantly, he had finally recognised that, after years of sterling service, their time was up.

Such a scene could bring a tear to the eye of anyone who has ever been forced to bid farewell to an outfit as dear to them as their next of kin. It would also cheer the model and fashionista Eunice Olumide who, among other things, campaigns for sustainability in her industry. After her talk last weekend at the Boswell Book Festival at Dumfries House in Ayrshire, I heard she had encouraged her audience to wear their clothes at least 30 times before discarding them. Not for her a one-night stand with ball-gown or palazzo pants. Clothes are not just for Christmas, they are something with which to establish a relationship.

At least one of her listeners was already on message. The journalist chairing Olumide’s event was wearing a 30-year-old suit, which looked as if she had picked it off the shop peg that morning. Putting aside the fact that a lot of us would struggle to squeeze into something we’d owned for so long, it was a timely reminder that while the extremes of fashion outlive their best-before date faster than a camembert, the finest clothes are timeless.

If you are already thinking 30 outings is the least you’d expect, chances are you could not be called a peacock or bird of paradise. Most likely you are one of those thirled to a self-imposed uniform, be it office suit or jeans. Sadly, I am of that persuasion. When getting dressed I rarely dig below the topsoil or forage beyond the most easily-reached hangars or shoes. Clearly it was for people of this nature that Harris Tweed was invented. Thanks to Hebridean looms, the idea of buying something that will “see me out” still flourishes in certain quarters. Years ago, when my husband interviewed Jackie Collins – who was resplendent in scarlet-zipped jumpsuit – she took one look at his elbow-patched Harris Tweed jacket, by then approaching its 21st birthday, and said: “This is some kind of joke, right?”

It would be nice to claim that the narrow field from which I select garments is an environmental and political statement, but that would be misleading. My wardrobe is a sorry depository, most of its contents languishing forgotten and unloved for years on end. Like half the population I’ll wear underwear until the elastic frays, but dressier items can lie in cold storage for months while I get used to their presence. One such purchase, a snazzy woollen jersey bought before Christmas, is folded in a protective bag, awaiting the clocks turning back this autumn. I’m just praying the moths haven’t by then invested in equipment capable of boring through plastic.

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Regrettably, the dogged use of a capsule wardrobe is often not an indication of an eco-warrior or trend-setter but someone indifferent to style. Either that, or a reluctant shopper. While I can admire beautiful clothes and those who wear them, I loathe trying things on. I do have one or two lovely pieces, but they are usually bought on a whim, often on holiday, when I am window-shopping at ease. Back home, on the high street, I find the deed has to be done on the SAS principle of going in under cover, and getting out at top speed before anyone spots me and advances to offer help. In terms of potential misery, the idea of hiring a personal shopper for a couple of hours is up there with volunteering to visit Mars. You might think online purchasing is the answer, but that’s about as effective as trying to hit a bulls-eye blindfolded.

The advent of Snapchat and Instagram seems to have accelerated the trend of disposable fashion, especially in those with serious social lives. Yet when newspapers trumpet the reappearance of celebrities’ previously-worn garb, what hope for the notion that it’s the person inside, not the costume itself, that matters? Changing attitudes to clothes, and their purpose, is the real challenge here.

The biggest culprit in most wardrobes is the statement piece, bought for a special occasion, that has done service only once or twice. Even when borrowed by friends, it’s lucky to have five wears, let alone 30. To address this problem there are, of course, places that hire out occasion wear. Yet they are not a cure-all. One woman spent £200 on a spectacular gown to attend a wedding, during which a fellow guest burned a hole in it with a cigarette. As a result, even though it was ruined, she was obliged to buy it at cost price – £4,000. No-one could call that sustainable.