Shopping for the person we are not and the life we don’t lead and probably never will is a wonderfully escapist activity. No cash needs to be handed over in this fantasy experience, although it’s possible that we might be able to shop our way that much closer to actually being that person. Or that’s the idea.

So, however unrealistic it might be, picture, if you can, an amalgam of the cool, minimal, Paris–meets–downtown–New York style of Sofia Coppola and that of the nameless Girl, played by the exquisitely beautiful Maria Schneider in Antonioni’s 1975 masterpiece, The Passenger. Although Sofia’s generally monochrome T-shirt, denim, and navy cashmere wardrobe has very little in common with the gorgeous period floral satins and wafting color of Schneider’s character, they share an utterly compelling shrugged-it-on-and-rolled-with-it aura. They are travelers on the highway of life.

Naturally, there exists absolutely nothing of either of these women in the real me, but that in no way diminishes the pleasure of accessing a soupçon of their style. Although I am a journalist now in my 60s and rooted in London, with a shape that owes rather too much to my sturdy Ukrainian grandmother, happily this dream shopping need pay no attention at all to such reality.

Instead I share their blithe, lithe spirit, able to wear a scrap of a T-shirt and long-legged, high-waisted jeans and appear ridiculously elegant. I require little fussing over my appearance to look wonderful and am possessed of such naturally impeccable taste that the very concept of taste is redundant.

The author’s alter ego channels the minimal, Paris–meets–downtown–New York style of Sofia Coppola.

Take, for instance, an oversize cotton-poplin shirt. Perhaps a striped one from Charvet or Nili Lotan’s Kristen style, or even the Row’s Astrea cotton number. This will be worn makeup-less, naturally, with tousled hair (or perhaps piled up and held by an Alexandre de Paris hairpin) and, possibly, some denim, although, ideally, just a pair of bare legs, to pad about home or wake up in a foreign hotel room with a view over a desert or ocean. Failing that, a pair of crisp but loose pajamas, such as the stripy number from the Alex Mill x Air Mail collaboration in mannish traditional stripes, would do the trick. It’s the easy androgyny that is both sexy and winsome.

Shopping for this alter ego is dictated by the appreciation of simple luxury. My fantasy self homes in on the allure of smooth lines, pleasure of touch, uncomplicated color. Which is why cashmere plays a key role. Is there ever a time when another cashmere sweater is not a good idea?

Funnel or crewneck are the shape—never a V, which risks a glimpse of cleavage—and the simpler the better, such as the Salie 66 Dakota, a classic in gray or navy, a thick cream from Khaite, or, obviously, anything by the Row. By the way, did I mention that price is never an issue in this dream shopping? Her cashmere jumper is enhanced by a pair of Oliver Peoples sunglasses with their nod to the style of writer Jane Bowles. And in an ideal world, this would all be paired with a Cartier tank.

Unlike me and my chaotic closet, my alter ego doesn’t need to wade through rails of mismatched pieces that might cause a wardrobe therapist to think they belong to a chronically indecisive person. (They would, by the way, be wrong.) Her possessions are not only in perfect taste but are slimmed down to a functional collection, so it would be a matter of minutes to toss a few pieces into a Métier Incognito Large Cabas in Marrakech suede and head off—anywhere. She is a traveler, not a tourist. Despite her beautiful clothes, Schneider’s character in The Passenger appears to be traveling with no luggage at all. Perhaps the ultimate luxury.

No luggage, just the essentials. A real camera—a Leica compact digital—although, just possibly, she would have sourced an original analog version. And, ideally, a cherished Montblanc fountain pen. She’d have a Smythson diary because they look so lovely, even if she is not bound by appointments and long-held commitments. And a deliciously evocative scent such as Hermès Eau d’Orange Vert shower gel—a brand, incidentally, that celebrates the pleasure of travel—will accompany her everywhere. It’s a wonderful life.

Alexandra Shulman, the longest-serving editor of British Vogue, is a columnist for The Mail on Sunday and the author of the memoir Clothes … and Other Things That Matter