The world’s coolest Rock ‘n’ roll stylist William Gilchrist on what it means to be the sixth Rolling Stone

William Gilchrist is sitting at the bar of the Club at the Ivy, a martini (vodka, stirred with a twist) by his side. Perched on a bar stool, he scribbles into a leather notebook with his trusted fountain pen "A Pelican – they don't leak on aeroplanes." Gilchrist is all about detail, quality, practicality and, of course, great design. He is constantly alert, often jotting down ideas or snapping a product or look that catches his eye with his Sony X 100 camera which is tethered to his person with a lanyard "otherwise they tend to go walkies."

Gilchrist is one of the single biggest names in London fashion, having styled for L'Uomo Vogue, Versace, McQueen, Moschino and Arena. Now based between London, New York and Naples, his current client list ranges from media moguls and tech titans to The Rolling Stones and Jude Law. Born in Nottingham to nomadic expats who met skiing in Iran, his early childhood was spent between Saudi Arabia, Mauritius and England. Summers were spent hanging out with his punk older sister and it was then that his love of style began to evolve. "It was exciting – part fashion, part music, part art. It was rebellious, that's what attracted me," he reminisces.

Gilchrist's rebellion often got him in trouble – his British schoolhouse master took a dislike to him and to his treasured first punk outfit – a parachute shirt and trousers from Vivienne Westwood's Seditionaries collection. "I came back one evening to discover that my cupboard had been emptied; anything he deemed dodgy, he'd burnt – including my Seditionaries clothes."

After an art foundation in Oxford, Gilchrist went to the London College of Fashion and formed a passion for tailoring: "I liked the precision of it," he says. He made and showed his own clothes before landing a job in a Milan design studio at the end of the 1980s. "I hated it – going to the same place every day wasn't for me but styling interested me." Gilchrist got a job assisting one of Milan's biggest stylists but was fired for being "the worst assistant ever!" Gilchrist grins. "She was lovely. She also ran an agency and said: 'although I think you're stupid right now, I can see you're not stupid so I'll take you on as a stylist'."

Gilchrist kicked off his styling career at the top and has stayed there. He's worked with Buffalo creator and stylist Ray Petri, myriad glossy men's magazines, and designers from McQueen to Moschino. However, at the beginning of the noughties, a last-minute booking for a job in Paris took added another (very rock'n'roll) string to his bow. The stylist for the Rolling Stones album cover shoot had gone down with food poisoning and they needed a replacement urgently.

The shoot went well and a few weeks later Gilchrist got a call from Mick Jagger's office asking for a meeting. "Mick asked if I had ever styled stage clothes – they had a world tour coming up. I hadn't but I loved the band and, with the help of a great team, understood the scale. I landed my dream job." >>

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You've been working with The Rolling Stones for nearly 15 years now. What does that entail?
It's so interesting. They are all very different personalities and that's what I enjoy. You can't dress the Stones – you can provide them with suggestions but ultimately, what they wear is their decision. Their outfits change every night. I talk to them, I choose things and then show them colours and examples. They get style and they get the style that suits them. I don't care about labels, I care about how clothes look and their comfort. It is an organic journey and a really enjoyable one. I'll be there in rehearsals and at the start of the tour to get fittings done. When I started, the tours were very long – 110 dates – so I used to pop out regularly but the tours are much shorter now so I only go out if I'm needed.

What has to be taken into consideration when choosing clothes?
Mick doesn't stop for two hours so practicality, temperature and movement need to be considered, he needs to be comfortable. He may change four or five times a show, Ronnie will change three times, Charlie can't change – he doesn't move from the drums – and Keith may change his shirt. Colours are important. This is something Mick told me when we first met. He said: 'If someone is sitting on the back row, they paid a lot of money for a ticket, I want them to know who's who.'

And you also style Jude Law?
Jude and I met in LA on a shoot for Arena magazine. We clicked that afternoon and 20 years later we are still friends and collaborators. He is aware of fashion and isn't scared to try new things. Jude has got a really good instinct – you could chuck a tablecloth on him and he'd carry it off well – but I mainly style him for events. He's perfectly capable of finding the outfits himself but he is so busy that having someone he trusts to sort clothes out allows him to focus on other stuff. >>

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You also style many non-celebrities, how does this work?
Pretty much in the same way, by getting to know my clients and understanding their lifestyles. A stylist is a bit like a sommelier – you consider the individual, you weigh up the particular occasion and its various ingredients and you suggest something suitable that would work. My clients are all busy people – tech CEOs, entrepreneurs, music industry moguls. Some I work with year- round and suggest wardrobe updates regularly, others just give me a call when they need help for an event, and some travel a lot so I shop online for them and get things delivered to their hotel.

What's the key to dressing well?
Detail and fit – whether your clothes are high street or high end. It sounds really obvious but so many men wear clothes that don't fit properly. I bought £30 chinos from M&S and got them re- tailored – of course the fabric would be better in a £300 pair but for a pair of chinos it's good enough. The fit is now great and they're fine for running around in.

What would you suggest spending money on, then?
Shoes. You can't go low on shoes. And every man must own one bespoke suit.

What else would you suggest for a man's capsule wardrobe?
Definitely a lightweight trench coat or rain coat. A white shirt and then, depending on the person, a crew neck, V-neck or roll neck. And a dark blue suit (or navy depending on skin tone) – if you are going to wear it a lot, get it custom made. I also like a good dinner suit – tailored, good fabric, well made. Whether you are wearing it twice a week or twice a year, it's important it looks good. I also really like an unstructured double-breasted jacket – I'll wear one with a T-shirt in summer and a roll neck in winter.

To read the full interview, or to find out how to book a personal consultation with William Gilchrist, check out our latest issue of Tempus now