Ubiquity could arguably be fashion's ultimate goal. At its most banal the industry's purpose is to sell clothes, after all. More loftily, changing our perceptions of dress, particularly on a grand scale, is the sartorial Holy Grail.

Yves Saint Laurent, for example, often said that he wished he'd invented denim. This brings us neatly to the boot-cut jean, formerly seen as some kind of failsafe wardrobe solution to everything from flattery to comfort, and now about as fashionable as... well, about as fashionable as the neat little stiletto heel and mid-length jacket that were inevitably worn with it.

This time around, this silhouette had its roots in the collections of Tom Ford for Gucci in its mid-Nineties heyday. How long, lean and louche did the likes of Kate Moss appear in boot-cut velvet trousers, worn low on the hips and with a skinny shirt, preferably undone to the navel, though not in a Barry Manilow kind of a way. Alexander McQueen's bumster, more low-slung still, and with a kick at the ankle, also had its part to play. Whatever, it wasn't long before this trouser shape was available everywhere and women the world over worshipped at its unusually female-friendly altar.

How times change. Despite numerous attempts to bring back boot-cut denim (below) and its more extreme relations, the bell-bottomed or flared pair of jeans, its very omnipresence has ensured that it is, by now, dead in the water, worn by those who don't really care about fashion at all on the one hand, and by the stuck-in-a-rut WAG on the other.

Boot-cut jeans are the new leggings, then, while leggings, conversely and characteristically perversely, are the new boot-cut jeans. Confused? Well, boot-cuts are today nothing more than a lazy, middle-of-the-road look, more Boden than Balenciaga. Balenciaga designer Nicolas Ghesquière, incidentally, was responsible for quite the most enviable boot- cut trousers in fashion history. For now, it's safe to say that he wouldn't touch them with a barge pole.

So what to wear? Skinny jeans – very skinny jeans, leggings, jeggings, and so forth – have clearly proved impossible to shift, best worn with tough ankle boots and a cropped skinny jacket that is more boyfriend than obviously feminine in flavour.

Wear them high on the waist to avoid the muffin tops that go hand in hand with the hipster variety. The slouchy skinny is even more fashionable though: relaxed, cool and less show-off slender than its predecessor. Sisterly! Marvellous.