Even Paris designers have had to come right down to earth. And next season that means giving women what they really want: modern, sexy, wearable designs. Carola Long reports

After successive seasons exploring austerity, then fantasy, the Paris collections for autumn/winter 2009 were about reality. Many designers were facing up to what sells, what women want to wear in a crisis, and what their houses do best.

"People keep trying to divide designers into optimists and pessimists, but me – I'm a realist," Alber Elbaz told Style.com. "I thought with my heart about what women need from fashion – dresses, suits, blouses, coats. Life isn't just parties and lunches." Of course, the notion of reality that informs £2,000 dresses is all rather relative. Many of Lanvin's customers will still be wearing his sensitively tailored dresses and suits to parties and lunches; but they will look like discreetly sexy, modern superwomen rather than social butterflies while they do it. And when the inevitable copies of the Paris collections hit the high street in September, so will the more budget-conscious shopper.

While designers were trying to stimulate pure desire with colour and decoration last season, for autumn/winter, many, although not all, were offering their customers a welcome opportunity to wilfully confuse it with need. Meanwhile, many labels, even the usually über-conceptual Hussein Chalayan, were also capitalising on the most commercial idea of all: sex.

At Lanvin, bow-tie wearing maestro Alber Elbaz created skirts, jackets and dresses in black, stone and nude with an easy, luxe confidence and elegance that suggested post-power dressing. The look had more than a hint of Paris in the 1940s, with wrapped jackets cinched by thin belts, fitted dresses and pencil skirts. Flourishes came in the form of undulating drapery – a key motif across the collections – and a way of adding femininity without frivolity, thus keeping the look wearable and strong. The Dries Van Noten collection also had a 1940s feel, with characteristically easy, softly tailored trousers, knee-length skirts and wrap coats in block shades of saffron, camel, royal purple and tangerine.

The YSL show created a similarly Parisian, bourgeois look. These were exquisitely tailored, everyday clothes for real– well, a charmed kind of real – lives, with whip-lashings of sex appeal. In other words, it was turbocharged YSL. The designer Stefano Pilati's leather pencil skirts, oversized, perfectly tailored men's pinstripe blazers, and a leather corset evoked Helmut Newton glamazons, while white shirts with voluminous sleeves or a bow at the neck, and tailored grey-wool pencil skirts suggested a simmering undercurrent of bourgeois sexuality – perfect for the kind of characters Catherine Deneuve, who was seated in the front row– used to play in her heyday. Glenda Bailey, editor-in-chief of US Harper's Bazaar, observed that, "Yves Saint Laurent's legacy has been a big influence over designers throughout the international collections this season. It comes back to the feeling of power he gave to women."

Bailey traces several of this season's key trends back to the economy, saying, "When the world is spinning out of control, we need to feel confident and strong. That's why the Eighties are back, and that's why designers are doing shoulder pads and tailoring, anchored with belts and strong footwear."

All of the above were in place at Balenciaga, where drapery also struck a keynote. The designer Nicolas Ghesquière forsook the futuristic, space-waif look that pervaded his last collection to come back down to planet Earth. Not that the show was down-to-earth in the proverbial – or price-tag – sense. These weren't exactly clothes for emptying the washing machine in, but they were more commercial than last season, reflecting the brand's plans for a steady expansion that retains its prestige. Gleaming draped-satin tulip skirts and harem trousers in black, navy and chocolate, glittery jerseys and crystal embellished cuffs were followed by 1980s-style draped dresses in splotchy prints from the house archive.

Junya Watanabe also made use of draped techniques, as he knotted, twisted and wrapped black duvet coats with sculptural precision. In his hands, the usually cumbersome fabric looked almost as pliable and fluid as the lighter materials he draped and swagged into long dresses. A similar technique appeared alongside masculine coats at Yohji, who showcased the delightfully simple red shoes he has collaborated on with Salvatore Ferragamo. While many of the sharp, Eighties shapes around suggest pulling yourself together and fronting up to the world, Watanabe's coats were more about cocooning and protecting one from the big bad recession – and, of course, they looked pretty darn warm. Other forms of self-preservation were on show, from Balmain's armour-like silver sequined dress with exaggerated shoulders, to Hussein Chalayan's leather breastplates suitable for futuristic warriors. Manish Arora, who moved to Paris from London Fashion Week in 2008, even showed dresses with a knobbly texture and two heavy-lidded eyes that looked as if they were made from the gnarly skin of a rhinoceros or an armour-plated armadillo. When reality bites, there were dresses aplenty that offered the sartorial equivalent of a panic-room.

Several designers took refuge of their own, in the reassurance provided by tradition and referencing their own house archives. At Christian Dior, John Galliano fused classic Dior shapes such as the Bar jacket, with fluid silhouettes and opulent brocade fabrics that echoed the Orientalists, while at Chanel, Karl Lagerfeld was inspired by the Regency dandy Beau Brummell's penchant for cravats, using it as this season's twist on the iconic Chanel monochrome for a show that riffed on black day dresses, coats and suits. The white ruffled collars and cuffs were even detachable, offering consumers recession-friendly, realistic versatility in the form of two looks for the (considerable) price of one.

While the Parisian labels were going back to their roots with classic, sexy bourgeois shapes, other labels were true to their more radical roots. Rei Kawakubo was on fire at Comme des Garçons, with a show that played on tensions between toughness and vulnerability, masculine and feminine, with delicate pink net wrapped around military khaki, glittery pink hearts on veils and bright pink hair, combined with heavy brogues. Witty touches came from trompe l'oeil suits painted on to army fatigues, and toes painted on to shoes.

The British maverick Alexander McQueen was also revisiting his own archive. However, this was no obviously commercial greatest-hits collection, rather it was a new and challenging remixing of themes, such as his early, anti-fashion bondage pieces, bird motifs and Victorian shapes. A huge pile of rubbish – taken from previous show sets – on the catwalk, and blow-up doll style exaggerated lips gave the show a sinister, kinky, apocalyptic air. The clothes – sculptural jackets in blown-up houndstooth, shaggy fur jackets, bondage leather jumpsuits, and Victorian Gothic evening dresses in optical prints and angry red and black evoked a cross between Leigh Bowery and the Wicked Witch in Snow White. Forgiving the comparison to a criminal mastermind, it put me in mind of the description of the Joker in The Dark Knight – "Some men just want to watch the world burn". This was thanks to the sense of rebellious revelling in the world's impending destruction, and building exhilarating, if dark art, from chaos. Of course, McQueen knows exactly what he is doing by reminding people what a skilled showman he is, and in a season short on radicalism, this brooding spectacular was all the more arresting.

Catwalk notebook: Key trends

Draping: At Balenciaga on tulip skirts, 1980s dresses and harem trousers. Also at Junya Watanabe and Yohji Yamamoto.

Cloaks: Duvet-style at Junya, regal at Giambattista Valli.

Forties: Post-war soft tailoring at Dries Van Noten, Parisian sirens at Lanvin.

Eighties: Boxy embellished jackets à la Michael Jackson at Balmain, hot pink and luxe ra-ra skirts at Louis Vuitton.

Shaggy coats: At McQueen, Stella McCartney and made from looped tape at Martin Margiela.