Business & Finance Club - Beauty : Rarely do we get such a clear and consistent message from the catwalk about a new beauty direction as we did this season. As far as hair goes, there was no mistaking it: big is back.

Unlike the big of old, though - a tumbling mane fortified with hair extensions - big hair this time is high and controlled. See the evidence from the autumn/winter 2010 runways, where there was a strong Mrs Robinson vibe going on: at Prada, a parade of retro beehives; at Giles Deacon, Rochas, Karl Lagerfeld and Chanel, frenzied backcombing, which made the girls' heads look disproportionately large; at Michael Kors and Christian Dior, softer height, achieved with rollers, comb-teasing and spray, making, for Dior, mountains of candyfloss, and, for Kors, windswept crowns and fluffy low ponytails.

While height has supplanted fullness and structure has replaced movement, there were several interpretations of big within these parameters. For example, the looks created for Prada and Rochas were retro and helmet-like -the most rigid of all the new big looks.

For Prada's show, stylist Guido Palau was apparently inspired by the immaculately groomed girls in the typing pool in Mad Men, the TV show set in a fictional New York advertising agency in the early Sixties. Although they were still structured, the backcombed creations he did for Christian Dior were much more fluffy and eccentric.

It goes without saying that the requirement for this season's big-ness is length - locks to your shoulders at least. You will also need to make friends with a backcombing brush - most stylists use the pocket-sized Mason Pearson Boar Bristle Brush (£29, hqhair.com ) - and acquire some root-lift product and a gravity-defying hairspray.

Extensions have been succeeded by hairpieces and mesh cushions to give stability and height where there is insufficient length. Palau used mesh to build Prada's beehive-like updos, which he described as 'classic French hairdressing done with a very chic, uptown nod to the Sixties'. He primed the girls' hair first with Redken Thickening Lotion (£9.95, hqhair.com ), divided the top part into two sections and laid them over the mesh, before setting hair with trusty Elnett Satin Supreme Hold Hairspray (£5.89, Boots). His finishing touch was a plaited rope - seek out a braided headband (£11.50, hothair.co.uk ) wound around the updo.

Far softer, but still built with the backcombing brush, were the teased confections at Dior and Nina Ricci. While Palau channelled early-era Priscilla Presley for Ricci's girls - high, long and trailing loose, the finished look was more freestyle at Dior, depending on the length of the girls' hair. Some models had their faces framed by side puffs that evoked 18th-century wigs, others turned to reveal a contrasting tight plait at the back, and a few looked almost mad-woman-in-the-attic, with clouds of hair around their head created by some serious roller and backcombing action.

While backcombing is the basis for any style this season, be it a high chignon or low-slung pony, and gives a fuller, dressier look, it does not have to be rigid - at Chanel, hair had the most movement but was made to look big at the back by being gently caught over a lightly backcombed base so that it appeared to be tucked under.

Chanel and Kors showed us the best big ponytails - the ones created by Orlando Pita for Kors were particularly beautiful. He was inspired by an image he had seen of two of the original Seventies supermodels, Patti Hansen and Lisa Taylor, looking carefree and windswept in a drop-head car, and wanted to re-create that mood.

To do it, he didn't rely on a wind machine, but re-created the same effects with the skill of a sculptor so they would last - another example of how contrived the new big-hair looks are, though they don't appear so at first glance. He coated sections of the models' hair with a volumising spray (try Fudge Medium Hold Bodifying Salt- Enhanced Texture Spray, £9.55, feelunique.com ), which builds body as it coats each strand, then blow-dried the hair. When it was dry, he fastened it back into a ponytail, twisting a clutch of it around the band, cleverly injecting controlled frizz through the length for continuity.

The picture Pita was painting was that this gentle 'mussing' had occurred spontaneously, having been stirred by the wind during a drive in a convertible Ford Mustang. The reality was that a lot of work went into creating that spontaneity. Control was a common thread running through all the big-hair catwalk creations for this season.

The new interpretation is contrived and groomed, the opposite to the full and free-flowing 'big' of yesterday. In fact, this composed new standard already makes those mountainous, WAG-like skeins of hair look very outmoded.