Vintage material

They all look stunning to me. Pictured in silks and satins, she is lounging upon her new, luxurious bedding range.

But then, has anyone ever taken a bad photograph of Twiggy? She has been immortalised by every great name in the business, from David Bailey to Richard Avedon, Steven Meisel and Annie Leibovitz.

Moving seamlessly from the waif-like, six-stone icon of the Mod generation to the saviour of Marks & Spencer, she has won plaudits for her acting on stage, screen and television along the way. She's starred in hit shows in the West End and on Broadway and is perhaps even more famous in the US than she is here – where her face is as recognisable as that of the Queen – especially after becoming a judge on America's Next Top Model.

She's a successful fashion designer, with her own range of mail-order clothes for Littlewoods Direct, and has achieved new success as a model, thanks to the M&S advertisements. "The problem with my career is I do so many different things," she says, adding quickly that it's actually rather a nice problem to have when you are on the cusp of your sixties.

"You know, I'm as shocked as everyone else. Who would have thought I'd still be modelling at 59? It's mad! But I love it.

"They're good, aren't they?" she says of Aris's photographs, peering at me over the top of her reading glasses. Her large, denim-blue eyes are expertly shaded in smoky grey and fringed by long lashes, although she no longer spends 90 minutes doing her eye make-up, as she did when she was the face of swinging London more than 40 years ago.

Back then, she would layer three pairs of false eyelashes over her own, painting extra "twigs" on to her skin with eyeliner so that she had lashes as long as spider's legs. (She got the idea from a schoolfriend's rag doll.)

She'll be 60 next year and she looks marvellous, with her tumble of blonde hair and slender figure, although she has more womanly curves nowadays than when she was the original, stick-thin supermodel, the Bambi-eyed, leggy epitome of Sixties style.

Today, Twiggy is wearing a baggy, blue cotton dress – which on anyone else would look like a sack – chunky gold jewellery, and battered cowboy boots over bare, tanned legs.

We are sitting on a velvet-draped sofa in her drawing room, the balcony of which overlooks a leafy London square. She and her second husband, actor Leigh Lawson, sometimes sit out with glasses of wine on balmy summer evenings.

They will do so later, because it's a beautiful day and she's cooking a special family dinner to celebrate the 32nd birthday of her stepson Jason, known to all as Ace. The small party will be attended by her 29-year-old daughter Carly and her boyfriend. Twiggy and her daughter are close to Ace, whose mother is the actress Hayley Mills, with whom Lawson had a relationship in the 1970s.

"I love being a wife," Twiggy says. "And I love being a mum to Carly and Ace; I don't feel I'm much different from most people. I'm very ordinary, down-to-earth and very normal."

Clearly a dedicated homemaker, she loves sewing and runs up most of her own curtains and soft furnishings, especially for their house in the country, as well as many of her own clothes. Despite all her fame and success, she's adamant that the two greatest achievements of her life are Carly, and her happy second marriage, which has endured for more than 20 years. Carly is the only child of her first marriage to the late American actor Michael Whitney, who died when Carly was five.

Today, Lawson cheerfully answers the phone and the doorbell, both of which ring constantly while Twiggy does this interview. She had a long wait for her Prince Charming, she wrote in her 1997 autobiography, Twiggy in Black and White, but it was obviously worth it.

Their flat is filled with pieces of art nouveau and art deco, and many large paintings, photographs, drawings and posters, some of Twiggy herself and Lawson. In the loo, there's an original, signed cartoon of Snoopy on the roof of his kennel, sighing: "I think I'm in love with Twiggy." There are dozens of silver-framed, family snapshots on every surface.

Being in Twiggy's home, I tell her, is rather like stepping back in time to the old Biba store in Kensington. There's a life-size china tiger beside the French windows, a massive Buddha on the mantelpiece and vases filled with tall plumes of dried grasses, as well as lots of flowers and candles. "Exactly!" she exclaims. "I loved Biba, still do. In fact, I've just interviewed Barbara (Hulanicki, the founder and designer of the archetypal Sixties and Seventies label] for a TV programme on British fashion. I adore her!"

The programme is BBC 2's upcoming documentary, British Style Genius, which looks at everything from high street style to haute couture and features Vivienne Westwood, Kate Moss and, of course, Twiggy. She is also fronting Twiggy's Frock Exchange, a new BBC2 autumn series that will show how you can give your wardrobe a new lease of life for free. Based on the American craze for clothes-swapping parties, each programme will feature celebrity guests donating clothes from their own wardrobes.

Both the documentary and the series are due to air next month. Meanwhile, her new book, a lavishly-illustrated style companion, Twiggy: A Guide to Looking and Feeling Fabulous Over Forty, has just been published. It's filled with fabulous photographs by Aris and Sarah Maingot, and elegant illustrations by Tina Berning. There's plenty of practical advice, with hundreds of tips on how to make the most of yourself once you are a woman of uncertain years.

"Crossing the middle-age threshold doesn't mean you have to get out your comfy slippers and your flannel knickers," writes Twiggy. If there is one thing she has loved about getting older, she says, it's the liberating feeling of caring less about what people think of her.

"I'm not going to say I'm in love with my wrinkles," she remarks. "But I've certainly learned to live with them. There's no point in wishing them away. To chase youth is to chase a pot of gold at the end of the rainbow. Follow the route of lip plumping, bum tucks, tum tucks, boob implants and Botox, and the chances are you might well end up looking like an android."

However, she confesses: "As I approach my 60th year on the planet, I haven't had any 'work' done, but who knows? I might get to 65 and have a change of heart."

Either way, Twiggy is adamant that women should not be pressured into pricey cosmetic procedures to fight the inevitable.

"Everywhere we turn, the current beauty ideal is to be skinny and young," she says. Of course, she was once skinny (although she says she ate like a horse) and young herself. Neasden-born and bred, she was 16 when the Daily Express pronounced her The Face of 1966.

As for being skinny, the first size zero, she laughs loudly when I mention the Sixties sticker campaign "Never Mind Oxfam, Feed Twiggy". She couldn't put on weight until she was in her thirties and had her daughter. "Unfortunately, the fashion industry thinks clothes look better on skinny people.

"Look, who are the two most successful models in the last 40 years? Me and Kate Moss, both of us small women. But the media is also responsible for putting pressure on girls to be thin. They shouldn't."

None the less, from as far back as she can remember she was shy and insecure about her looks, whether it was her flat chest, her skinny legs or how to cope with her body as it has changed. Angel-faced Twiggy insecure? "Nah," she says, cackling with infectious laughter. (The raucous laugh could, as someone once remarked, shatter eardrums.) "I never looked like an angel. I always thought I looked more like a duck. And I certainly never thought I was beautiful.

"I never loved what I looked like. Now, with the benefit of hindsight, I can see I was different. I was given a body that worked for photographic modelling and a photogenic face. Ironically, if I'd had a fairy godmother when I was 14, I would have begged her to make me more voluptuous and shapely. I desperately wanted to be Brenda Lee (a Sixties' pop star, the original Miss Dynamite]. I wanted bosoms, a waist and hips and to wear high-heeled, pointy shoes and big skirts."

Instead, she was "this funny, duck-like creature with skinny legs, a face with big eyes and a blonde crop of hair on top". Now, though, Twiggy believes that every woman has something unique she can bring out and enhance. Ah well, we all need miracles, I tell her, especially those of us who wake daily to ever-larger bags under our eyes.

"Every wrinkle tells a story," she consoles. She's proud of her own laughter lines. "They're wonderful, they add character to a woman's face." However, Twiggy is adamant that once you're over 40, your skin needs tender loving care, hence her guide, full of wisdom culled from the many experts she knows, such as legendary make-up artist Barbara Daly, hairdresser John Frieda, and a number of highly qualified dermatologists, as well as fashion designers, such as Christopher Bailey and Stella McCartney.

A close friend of Stella's mother, the late Linda McCartney, Twiggy has known Stella since she was a babe in arms. Now Carly, a graduate of Edinburgh University, is on Stella's design team, much to Twiggy's delight.

BORN Lesley Hornby, Twiggy is the youngest daughter of Norman, a carpenter from Lancashire, and Nell, who was 41 when she found she was pregnant with Twiggy, who admits to growing up the spoiled baby of the family.

At 17, she was Britain's top model and at 21 she was a movie star in Ken Russell's musical, The Boy Friend. Never a party girl, she always went home at night to her beloved family. Nor has a whiff of scandal ever been attached to Twiggy, who has had only three serious relationships in her life.

Her first boyfriend was Nigel Davies, whom she met when she was 16 before he changed his name to Justin de Villeneuve and who, thanks to Twiggy's glittering fame, became one half of the most glamorous couple in London.

When she was 23, she split from de Villeneuve. Then she fell in love with Michael Whitney. Eventually she realised that he was an alcoholic.

After Whitney's death, she met Lawson, whom she'd been introduced to years before, at a supper party. Days later, they bumped into each other and he asked her out to dinner – and that was it. They married in America and honeymooned in Mustique. Over the years, they have often worked together.

He's a romantic. "I get flowers all the time, and jewellery. If I'm getting up early to do something, I'll find a note in the kitchen saying, 'I love you'. And if I'm flying off somewhere, there's always a message in my hand luggage. We're so lucky that we found each other. It's a miracle."

Twiggy: A Guide to Looking and Feeling Fabulous Over Forty is published by Michael Joseph, at 20.

Twiggy's top tips

Sleep

Use a satin pillowcase, it stops hair snagging and saves your blow-dry. It's also good for stopping wrinkles around the eyes.

Exercise

My favourite form of exercise is tap dancing, which I started when I was 20. It's great fun, works the whole body and the brain and you end up feeling like Fred Astaire! I still do classes and love every minute.

Bright eyes

When I wake up before my eyes do, I grab a bag of frozen peas from the freezer and alternate holding it over each eye. I can often be seen eating my toast at breakfast with one eye under the peas.

Lips

A little dab of illuminator at the bow of the lip is a nice effect for evening. Put on before lip liner and lipstick and it gives an instant pout.

Make-up sin bin

Avoid heavy foundations. Ignore their claim to cover wrinkles. They won't. Don't use frosted lipsticks. They make your lips look old, old old! Stay away from shimmering eyeshadows. They can seek out the crepe and showcase it.

You are what you eat

By eating healthily and for sustenance, there's no need to follow diets unless you have a significant weight problem. Even then, the best way to lose weight is to exercise and cut down on portions. Through my obsession with good food I've become a very happy cook – cooking is good for the soul.