The capsule wardrobe has always been cool. The capsule wardrobe is Françoise Hardy and Sade. It is Audrey Hepburn and Carolyn Bessette-Kennedy. It is all the heady intoxication of fashion with no hangover of buyer’s remorse. It is a magic pill to streamline your wardrobe, so no more tying yourself in knots figuring out what to wear.

Outfit repeating used to be something that fancy people wouldn’t be seen dead doing, like getting the bus

OK, so here’s the thing: as we all agree a capsule wardrobe is such a great idea, why don’t we actually dress like this? I’ve never nailed it and I know a lot of very fabulous, cool, clever women and most of them haven’t either. But 2020 might just be the year that is going to change. Because capsule dressing is no longer the sensible option, the one you know you should commit to, if only you didn’t keep getting your head turned by newer, more daring, more exciting, more instantly desirable clothes. In 2020, capsule dressing is where the newest, most daring, most exciting, most instantly desirable fashion is happening.

Sustainability is aspirational. Zoolanderish, yes, but also true. If sustainability means that we as a species get to continue living on this planet, then that seems to me to pretty much sum up our wishlist right now. A fabulous capsule wardrobe is the sustainable way – which is to say the modern way – to raise your fashion game. You can tell that sustainability has become glamorous because outfit repeating – which used to be something that normal people did all the time but fancy people wouldn’t be seen dead doing, sort of like getting the bus – has now become a badge of honour. Meghan Markle rewears dresses, Joaquin Phoenix sticks with one Stella McCartney tux through red carpet season.

The tagline of Wardrobe NYC, the front row’s current favourite label, is “luxury without excess”. Founded by designer Josh Goot and fashion director Christine Centenera, Wardrobe NYC is “the ultimate wardrobe for those with shared values and aesthetic”, which translates as pared-down urban minimalism designed in New York and made in Italy. The aesthetic is radically minimalist, but the price tag is seriously upscale, with £1,500 buying you a four-piece wardrobe, delivered as a set of blazer, shirt, T-shirt and leggings – just choose from black or white, and click your size. (It’s like a HelloFresh box, but with everything you need to look cool rather than to make dinner.) A four-piece, pared-back, day-to-night wardrobe commanding a price point usually ruled by the fancy party dress speaks volumes about the status of the capsule wardrobe right now.

What should your capsule wardrobe look like? Does a blazer and leggings work for you, or is it two black dresses and a camel coat? Or a grey trouser suit and two white shirts? The answer is in your wardrobe, says designer Maria Grachvogel. Now 50, Grachvogel has run her own brand since she was 21. “Open your wardrobe, take a look – and be honest,” she says. “There is probably a core 20% of what’s in there that you return to time and time again.” Whatever that 20% is – printed dresses, plain tailoring – “that’s your capsule wardrobe, right there. Those are your treasures. It’s about what suits you – but it’s also about who you are as a person and what kind of life you live.” Before you buy anything new, Grachvogel says, “ask yourself: is this going in my 20%? Is it going to be one of my treasures? Because that’s the only part of your wardrobe that matters.” She attributes her loyal customer base to the fact that “I have zero interest in selling women clothes that they won’t wear”.

Outfit repeating has become a badge of honour: Meghan Markle rewears dresses on royal tours

“We’re all so busy, no one has the time or the energy to spend hours standing in front of their wardrobe trying to figure out what to wear,” says Clare Hornby, founder and creative director of British “affordable luxury” brand Me+Em. “A capsule wardrobe means one you can rely on to make you look and feel good with minimal effort.” Hornby is a self-confessed trouser obsessive, as proven by Me+Em’s “transformer” trousers (in wide or narrow styles, around £170), which can be extended from cropped to longer length with a button fastening – endless research went into fabric and construction which could hold a chic silhouette in both modes. “Think about what’s practical for you,” she says. “If you work, then you need clothes that are smart enough for the office, comfortable enough for a long day, easily dressed up for after work.”

Grill successful modern capsule dressers, as I did for this article, and the blazer is a wardrobe building block that comes up time and again. “I wear one most days,” Hornby says. “At weekends I can wear joggers and a T-shirt, and a blazer pulls it together.” A cross-body bag – try Coach or Kate Spade, or John Lewis & Partners – is another piece that has become a seven-day staple. While no two capsule dressers are the same, a common thread is a balance of masculine and feminine elements. A blazer is paired with a dress, say, or sleek tailored trousers with a ruffle-trimmed silk blouse. A yin/yang of masculine and feminine adds interest without fuss, and allows you to tip the balance in either direction to suit your mood.

Capsule wardrobes require team players. They work when your clothes can jigsaw together to solve your problems. Fancy, limelight-hogging showpieces are a distraction best avoided. Jazziness is good, but keep it subtle. Subtle jazziness is quite French, and Parisian brand Sézane does a brilliant line in light merino sweaters with detachable collar detail, so that you can add interest without fuss or bulk – and, crucially, help you keep the colours crisp by not washing light and dark together. (Current styles include the Olga, a smart short-sleeve top with a detachable broderie anglaise frill at the neck, £77.) Cos make detachable hoods with dicky-style bib fronts which can be layered under a smart coat when rain is forecast, instantly streamlining your coatrack.

Last year, Debenhams launched Kley, which aims to bring “the ultimate easy enviable wardrobe” to the high street. The range is quartered under the acronym Life: “Luxury” is for leather skirts and silk blouses; “Important” is for fashion-informed seasonal pieces; “Function” covers waterproofed and hybrid pieces; “Essential” provides foundational tailoring and knits. “It’s designed by women, for women,” says creative director Lucia Heffernan. “Versatility is key. We have less time nowadays, but women still want to look and feel great in whatever they are wearing.”

With sustainability non-negotiable, we who love fashion are finding ways to tease our passion apart from overconsumption. As the world heats, capsule dressing looks cooler than ever. A streamlined wardrobe frees a little more of your time, your sanity – and the world’s resources. “A capsule wardrobe isn’t just quicker,” Hornby says. “It’s better.”

A blazer, a trench, a cashmere knit, a pair of good quality trousers, the ultimate silk shirt, plus a jazzy skirt – how six items make a seven-day wardrobe

• Trench, £290, by Reformation from Net-a-Porter

• Trousers, £129, from Whistles

• White Signature Shirt, £230 Equipment at Net-a-Porter

• Tiger-print crepe midi skirt, £150, from Ganni at Net-a-Porter

• Blazer, £150, from Next

• Charcoal jumper, £78, from Everlane

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