Watching him dress a head of hair is like watching a theatrical performance. His hands are small and smooth, with immaculately clean square-cut fingernails. He tweaks and flicks, flirting with soft strands of hair, poised and delicate. He bends solicitously across the motionless client, absorbed as he in this miniature drama, to gaze at her head in the mirror; then snips, and a millimetre of fine hair falls to the floor, instantly swept up by an attentive black-clad junior.
Nicky Clarke too wears unrelieved black: black suede Gucci loafers, a black wool jacket and narrow trousers, black shirt, black silk tie. The austerity is lightened by a silver chain bracelet, a heavy watch - looks like a Rolex - and a chunky gold wedding ring. His wife, Lesley - said to be a tough and formidable woman who is the brains behind the money side of the business - runs both the salon and the product range, quaintly named Hairomatherapy.
Women (his clients have included the Duchess of York, the Princess of Wales, Yasmin Le Bon and Jemima Khan) come to him because he gives them the briefest and most temporary illusion of naturally perfect hair. For a few magic moments, as they both gaze at the finished work of art in the mirror, rapt in mutual narcissism, he creates soft, fluid, impetuous hair; a youthful drift of ... feathers, almost ... perfectly shaped, artlessly artful. His own hair is the same colour and texture as the coat of a young fox. He wears it long, shoulder-length, and it looks healthy, expensive, sexless.
Nicky Clarke was born in 1958, into a south London family of six clever children. Their mother was Greek; their English father worked at Bankside power station, now being converted into the Tate Gallery extension. "I really ought to go and have a look at it," he says fondly. "I have great memories of the works party there - absolutely the best Christmas parties ever."
From the nostalgic way he talks about family life just off the Old Kent Road, it could have been another century. The children romped together in their huge back garden; they read books, were dragooned to do their homework; led a close and vivid life. "But even as a child I always took immense notice of how people looked ... probably far too much. My sisters were incredibly hip and trendy. For the first time it was the young rather than the middle-aged, upper-class who ruled the fashion scene. Even as a little boy I wanted to wear black, but I wasn't allowed to because in Greece it's a funeral colour.
"We were all very good academically, though our area of London probably didn't have the best brains. Every one of us went to grammar school. We had tons of books at home and could all read from the time we were four or five. I went to Archbishop Tenison's School from - hang on - 1969- 74, but they put me in the C-stream, which was a great shock after always being top of the class, so I didn't manage four O-levels and wasn't allowed to do A-levels. Suddenly I found myself, at 16, with my schooldays over, needing a job. It was a great shock.
"I had been interested in hairdressing from the age of 13 or 14, though I'd never seen it as a career. Hair, in our family, was always a bone of contention, because everybody in the world had long hair - this was the Sixties and early Seventies, Beatles, Stones, all that - but I had to have short hair because the school insisted we wore it above our collars. I never saw hairdressing as a career, though - what I wanted was to be a journalist.
"I've never been unemployed," Nicky says, "and I never would."
Easy to say, perhaps, since in his teen years jobs were advertised outside every factory and you could take your pick. He disagrees. "I see young, healthy people begging in the streets and I can't summon up the sympathy I would feel for an elderly person. I just think, where is your self-respect? Get up on to your feet and find something to do!
"It's this business with social security, whatever they call it. My beef is with people who are unemployable because they make no effort. When I was 14 or 15 I used to stack the shelves in Tesco's and I loved it. I can't remember skiving off. I took pride in what I did."
Within a few weeks of leaving school Nicky, just 17, had started work as the most junior of juniors in Leonard's salon, sweeping up hair, folding towels and making coffee.
"It seemed very special, this huge, chic, glamorous building, and (this was in 1974) I was being paid pounds 12 a week. I was living at home, thankfully, supported by my parents. Juniors today seem to have their own flats, or share, whereas the whole apprenticeship system is based on the assumption that you're still partly supported by your parents.
"To start with I was tremendously nervous and on edge, terrified of doing something wrong - but determined to learn as quickly as possible so as not to look a fool. I recognise myself in some of my juniors today - quite often the greenest and the quietest will make the best stylists in the end. It'san inner focus that desperately wants to learn the job."
The salon that has Nicky Clarke's name over the door is at the north- west corner of Berkeley Square. On a December evening its huge windows twinkle with the glamour of an ocean liner, freighted with wealth and perfumed luxury. Women draped in gowns and towels stare gravely at their mirror images. The walls are lined with magazine covers showing smooth- skinned young beauties crowned with lustrous, attention-getting hair. Photographs submitted for the 1995 hairdressers' award have pride of place. It seems odd, I tell him, that a three-dimensional skill like hairdressing should be judged on the basis of photographs.
"People do constantly complain and say it's not a fair assessment; but the judges aren't interested in how the hair stands up to a blast of wind or a hot theatre, that's not what it's about. It's about direction, influence and innovation in hair, and your record over the whole year as a stylist. Photographs are submitted anonymously - though yes, I dare say the judges can probably spot my work by now. Anyone can submit, from all over the country. They're whittled down to six finalists, who have to submit a new set of pictures, and who're also judged on their contribution to the industry."
How important was it for him to win? "If you have a competitive spirit - which I do and always have done - it's nice to win." He smiles engagingly.
Why are there so few top women stylists, and not a single salon where the name over the door is that of a woman? "I don't really know. I know plenty of good women stylists and at the junior stage we take on as many girls as boys, but somehow they haven't made it to the very top. Women themselves must take some blame, partly for being less ambitious; also, many interrupt their careers to have babies, and their priorities change."
Could it be that women prefer to be flirted with and flattered under the hands of a man?
"A lot of women do like that, but others like the camaraderie of having a woman do their hair. My bet would be that in two or three years you'll see a couple of star women hairdressers."
Back to the Seventies, where John Frieda - his senior by seven years - and young Nicky, who was made up to stylist after only 10 months, were among the leading lights under the Leonard name at the most elegant salon in London.
"I lied about my age, I told them I was 20 when I was only 18, so they put me on to the floor and I had a meteoric rise. I can remember doing my first set in the salon with the sweat just pouring off me, I was so nervous. But things clicked very fast. The penny was dropping all the time. I was taking home wig blocks and working on them till two or three in the morning. Sometimes I slept in the salon at night."
Nicky and John Frieda, then Leonard's top stylist, worked closely together for 16 years. When, in 1980, Frieda broke away to open his own salon, Clarke went with him. His salary doubled - to pounds 32 a week. Clarke was able to think about leaving home. But after years of harmony, he began to feel he wasn't getting his fair share of the credit, or the money. In 1990 he left, and opened the present salon under his own name. Not surprisingly, the relationship - and they had been not just colleagues, but best friends - turned sour. Frieda tried to sue Clarke, but after five years of legal wrangling, settled expensively out of court.
Now in his own business, its financial side in the safe, tough hands of his wife, Clarke can concentrate on doing hair and staying at the top. Not that he is a workaholic: with a son of nine and a daughter aged seven, he insists on spending long holidays with them twice a year.
He works five days a week, doing 9 or 10 heads a day. After 20 years, doesn't it ever get boring?
"I've reached the stage where all I want is to make hair that is flattering to women. I went through the bright blue hair and spikes period long ago - in the Seventies - and now I just like women to look beautiful. When each client leaves, I want her to look great and be happy. I'm still eager to please."