Julien D’Ys —who John Galliano once described as “part painter, part stylist, part pirate'—is pretty much the rock star of the hair world, and all the way back in October, I was lucky enough to have him do my hair on a shoot with Peter Lindbergh. I wasn't expecting much to really go down in the grooming department (the look? “chic, natural' and “relaxed, like herself') on this particular day, so color me mystified that, while I sat there admiring his set-up—the candle, the single white rose, the scarves, the red lacquer box full of light wood- and dark chestnut-colored hair combs, his scrapbook (which Garance photographed beautifully)—he somehow transformed my very straight hair into Greek goddess-y, beachy, wave-madness that was romantic, touchable, and stayed as is way after the shoot was over and late into dinner with friends—long after the equally masterfully-applied Stephane Marais eye makeup had melted into under-eye-puddling obscurity. How did he do it?

First, sections of my dry hair were wound into rolls that he clipped up (and that I subsequently threw a hoodie over, so as to roam around the set looking like someone’s grandmother lost in the frozen foods aisle) and set via a concoction sprayed from a label-less Windex bottle. “This is my own beach-salt-spray,” D'ys said, and his hair is what appears to be a series of faux-dreadlocks (in that sort of killer '90s movie way, where you know he bathes regularly but still gets that insouciant, mussed-up texture), which he explained he creates by washing his hair, twisting and spraying it with this same stuff. He removed the clips and tousled my hair with a blow drier, securing it half-up with one of the aforementioned combs and tying two sections of my hair into a textured knot below it. Note: I have since tried to duplicate the hair knot/comb combination myself. It has not worked, try as I might. It would appear that having your hair done by a hair genius does not, sadly, make you a hair genius. Such, I suppose, is life.

As for the secret ingredients in that spray bottle? One part Lustrasilk Set & Style Lotion to three parts water—shaken, not stirred. “The bottle is very retro, no?” he laughed, and friends, Lustrasilk looks straight out of 1950, and might be discontinued and actually be from 1950, but who am I to question greatness? If you cannot find it in your local beauty-supply store, where it would probably be gathering dust on a shelf, he e-mailed to say that Biosilk’s Beach Texture is his new favorite spray, no mixing required.

—Alessandra Codinha