Wear with flare: Prada sets the tone with brilliant bell-bottoms and sculpted sandals

Moody, n'est-ce pas? And well it might be. This, after all, is a straight-off-the-catwalk look courtesy of Miuccia Prada. Here's what she had to say backstage after her show in Milan last September, with regard to a fashion moment that is rather darker than might be expected, given that this is the summer season, traditionally a time of high spirits and blithe prints and colours to match: "This is the first time I've gone soft. There is nothing straight in this collection – like there is nothing straight in nature."

Of course, Prada's idea of soft is not of the fluttering, bias-cut petticoat variety. "Before, I wanted to show women as tough and powerful so I used thick fabrics," she continued, "fabrics with dignity. Shapes were vertical to represent strength. But I discovered women like soft, they like pretty. It was hard for me because if you use soft fabrics and cut on the bias, it is boring, all it does is show the body. So I did a new soft with experimental prints and fabrics."

As is often the case, this represents something of an about- turn from her concerns the previous season – it's small wonder that the rest of the world struggles to keep up with this designer. Last season, as any fashion trainspotters out there will doubtless remember, the first lady of fashion worked with materials that were generally stiffened and stood away from the body, and with tufted alpaca, which, she announced breezily, she knew wasn't particularly flattering but she didn't actually care. Colour, meanwhile, was what she herself described as "violent" – chemical orange and blue and green.

Fast-forward six months, and for spring/summer, Miuccia Prada says she was also focusing on women's private fantasies: "It was all about fantasy, and about fantasising also. I was not thinking of a particular woman's imagination but of women's imagination in general." She is, of course, aware that such fantasies are far from simple, or indeed steeped in anything as nice as sugar and spice, so there is a profound, if slightly twisted, romance to this vision of the inner woman and her meanderings.

This can be seen nowhere more clearly than in the case of the shoes – a completely different hand-finished pair was worn with each exit on the catwalk – finished with highly stylised flowers and ranging from the resolutely flat and brown, to the garden-coloured with sculpted spike heels.

In a season that will go down in history as being rooted in all things natural and even bucolic, Prada's was certainly the most Gothic interpretation of the theme. A more than passing nod to the 1970s, meanwhile, brings to mind a time in history when the first wave of feminism was in full flow, and with it the insistence on a female's right to express her desires, however complex or indeed unorthodox they might be. And that is something the designer herself experienced as a young woman first hand. There is something subtly sexual implied, then, both in the exaggerated curvilinear surface of clothing, and the intensely beautiful, predominantly muted colour palette.

Organza is the principle "soft" fabric of the Prada spring/summer season – and, indeed, of the spring/summer season as a whole – most instantly recognisable cut into wispy and decidedly whimsical dresses appliquéd with flowers, which fall somewhere between The Magic Roundabout and an Arthur Rackham illustration in appearance. The silk-cotton knitted waistcoat in a signature sludgy shade of green pictured here represents a more characteristically urban aesthetic – as well as Prada's ongoing love affair with sweater dressing – but even this is teamed with printed organza trousers that are significant not only for their diaphanous quality but also because they are flared. Yes, flared.

This, too, might not unreasonably be considered something of a controversial move, given that the uniform on the street – the odd pair of wide-legged jeans aside – has, for some seasons, been so resolutely skinny that anyone over a size eight, say, has struggled to wear it. Max Wall, anyone? An unlikely fashion icon if ever there was one.

Prada's flared trousers bring to mind not only flower power and the 1970s, but also the chic, wide-legged pyjama dressing favoured by Hollywood stars of the Thirties and Forties. They are far more feminine than the drainpipe, particularly given their weightlessness.

Where this particular designer leads, others always seem to follow, so a 1970s flavour, and flared trousers to match, have since sprung up everywhere, from D&G to Burberry for next autumn/winter. The serious fashion follower would do well, therefore, to start wearing them now.

You saw it here first: the Prada hit parade

* THE NYLON BACKPACK, FIRST CREATED 1984

Miuccia Prada had her breakthrough in the early 1990s, when her black heavy-duty nylon bags, complete with triangular black-and-silver metal tag, became a design classic. "I treated bags as if they were fashion for the first time," the designer explained. "This was something practical but also very luxurious. Those bags were more expensive than the leather ones because learning how to work with the nylon took three or four years."

* FORMICA PRINTS, SPRING/SUMMER 1996

When this typically minimal silhouette was first aired (below), the prints seemed more readily associated with the table tops in 1950s American diners than anything more obviously fashionable in flavour. The look was idiosyncratic, to say the least, and even dowdy. The colour brown, in particular, featured heavily, beloved by Miuccia Prada because she claims it's "the least commercial colour".

* ELABORATE SHOES, SPRING/SUMMER 1997

Miuccia Prada's relationship with shoes goes back to her childhood, when her mother decreed that she must wear them flat and brown: "I remember being mad about having a pair of pink-and-red shoes. I grew up envying pink-and-red shoes." As a woman, she was able to fulfil that fantasy by designing shoes that are sometimes pink and red, but, since the mid-1990s, also strange and increasingly elaborate.

* SINCERE CHIC, SPRING/SUMMER 2000

Miuccia Prada herself labelled this look "sincere chic" – it was bourgeois and proud and openly indebted to Yves Saint Laurent, one of the designer's longtime heroes. In its conservatism, this style was, in fact, radical, and its influence swept over fashion like a tidal wave, making the dark and distressed fashions of the avant-garde seem about as edgy as a pair of jeans.

* FURRY COATS AND KNEE-HIGH SOCKSAUTUMN/WINTER 2007

Transforming a woman into a high-fashion teddy bear was a particularly brilliant move (below). If it made her look big, then so be it. Skinny is just so boring.

Prada's knee-high socks, meanwhile, were also among the most copied garments of the season, quite something considering their proximity to – only whisper it – toeless popsocks.