I was doing hair backstage at the Mercury awards recently when Jake Bugg rolled in. “Do you want your hair doing?” I asked him. “Nah,” he said, running his fingers through his scruffy do. Bugg knows that it’s not rock’n’roll to have hair that looks too done, and that goes for the girls too. Haim have great rock hair: it’s superlong but not overstyled, carefree and anti-establishment. It also has lots of movement — that’s what makes it sexy. The minute you try and set it with hairspray, it’s ruined. But that dishevelled look is hard to achieve.

I met Kate Moss backstage at Glastonbury and she has the best rock hair. It’s not too polished or over-blowdried; it looks effortless, and the texture is supermodern. It is, in fact, a deconstructed blow-dry. That tousled bed-head look is tricky, because if you put tongs or rollers in it, the curl will be too even and perfect and you’ll look like a Chelsea mum. To get Kate’s texture, you have to tie your hair in knots. I mean it. First, straighten you hair so you’ve got a good, smooth starting point, then take two bunches of hair and literally tie each one in a knot or a big, fat, irregular braid. Then clamp the straighteners over it again, take the hair out of the knot/plait and blast it out with a dryer. You’re aiming for a matt texture, minus frizz, but with plenty of movement.

Choose your products wisely. Modern rock hair has got to look cool but not dirty. Dry shampoo takes the high-gloss shine off. Moroccanoil is also great, as it keeps hair smooth and looking product-free. Not all rock hair is long and free, though. Kelly Osbourne at the American Music Awards showed us that it’s possible to do a rock up-do. She adorned it with rows of spikes. It looked elegant, but the attitude was pure rock.

Josh’s advice

Cool: Saint Laurent SS14 (CATWALKING.COM)

Rock hair is difficult to get right — one girl’s rock can be another’s roll. Over the years, I’ve worked on some amazing people from the world of music, but one high point was turning David Bowie red.

There has been a real a resurgence of undone cool, thanks, in many ways, to Hedi Slimane at Saint Laurent. I love these accidental styles that look like no thought has gone into them at all, when actually a team of superstylists have deliberated over every tress for an eternity.

I have the pleasure of working with one such stylist, Eugene Souleiman, who has been described as the bad boy of styling, sending extreme styles down the catwalk for Haider Ackermann and Yohji Yamamoto, and creating wild looks for Björk. We are both tasked yearly to create global trends and subsequent images for Wella, and for SS14 this has resulted in a trend called Urban Native, a gritty edit of fresh, youthful expression. For colour, this meant faded neon pastels with a slightly melancholic feel. Colour is still rocking for spring, but we’ve just turned down the volume a bit. Kelly Osbourne’s dusty purple do is heading that way.

There are a couple of sure-fire ways to get “rock chic” hair — don’t overgroom or over-blowdry. For colour extremes, think platinum, raven black or even a kaleidoscope of colour all worn at once, like the model Chloe Norgaard.

Those who would like a hint of rock but want to keep the day job should use colour as an accessory — a hint of dove grey, a slash of pink quartz or a streak of black, or take blonde a few shades lighter and add a wash of pearl. There is a multitude of ways to make hair look more contemporary without having to go Gaga.