Oscars style: Carolina Herrera reveals the secrets of the perfect red-carpet ensemble

Herrera has become almost as synonymous with the Academy Awards as a weepy acceptance speech.

Carolina Herrera has a terrifying fashion pedigree. She attended her first couture show, hosted by Cristobal Balenciaga himself, with her grandmother aged 13, and set up her own label after encouragement from her close friend, legendary fashion editor Diana Vreeland.

Is it any wonder, then, that she has come to be one of the world's most successful red-carpet fashion designers? Her classically elegant gowns – notable for the use of vintage materials such as antique lace and taffeta, cut in a clean and modern style – have graced the backs of A-list stars such as Eva Longoria, Jessica Simpson and Uma Thurman. Herrera worked closely with Jackie Onassis for a decade and has forged a relationship with actress Renée Zellweger, who regularly wears her clothes at award ceremonies and on frequent public appearances.

Born 74 years ago into a patrician Venezuelan family, Herrera spent her youth between Caracas and New York, a stunning socialite with good looks and grace who was equally at home among royals as she was within Andy Warhol's arty-party crowd.

It wasn't until 1981 that she moved into the world of fashion design, after mooting to Vreeland an intention to create a range of textiles. "That is the most boring idea I have ever heard of," came her friend's caustic response. "Why don't you do a collection of dresses?" And so Carolina Herrera's eponymous brand was born. Her empire now encompasses not only the original clothing collection, but also a range of bestselling fragrances – including cult scent 212 and 212 Men – and a more accessibly priced diffusion line in CH Carolina Herrera, which offers the label's central tenets of easy chic and timeless style to a wider audience. This year also sees the launch of the brand's White Shirt collection, a selection of eight different takes on the wardrobe staple – one which Herrera herself professes to wear most days – including tie-waist details, pussybow collars, peplums and corset references, all modelled in a new campaign by British supermodel Jacquetta Wheeler.

I visited Herrera in her suite at Claridges during a recent whistlestop trip to London, where she held forth on the secrets of being fashionable and fabulous, and offered her fail-safe tips for glamour, whether you're walking down the red carpet or simply to the bus stop…

It takes a lot of effort to be effortless Style shouldn't be complicated. A simple dress is much more difficult to wear than one with ruffles and flowers and big sleeves. There is a perfection to a dress that is incredibly cut.

Some red-carpet dresses look like they've been lent to someone They're too tight and they're worn with shoes that are two sizes too big. I don't know how they walk. I like everything to be perfect.

Celebrities never pick from the collections because they want something made special No one is willing to wear a dress a second time, but real elegance is repeating a dress you like because it really fits. Now celebrities don't buy them, and they ask for another one and another one.

I've been dressing Renée Zellweger for 10 years I love her, because she loves fashion and has the most incredible figure. She loves fittings and doesn't have a stylist – she does it directly with me. She knows exactly how to pose.

elegance is a combination of things – some people have it, some don't It's not only what you wear, and it doesn't have anything to do with money or power. Sometimes you see women who don't have much to spend and they are very chic because they know exactly how to put it all together. Sometimes you turn around to look at a woman in the street because she has tied a scarf in a different way.

I like everything to look like you are wearing it because it's part of you When you're wearing something you feel comfortable in, you move better. That's why the most important accessory you can have is a full-length mirror.

I get dressed in 10 minutes – and I always have done If I have to go to a ball, maybe 15 minutes. I always manage it, because what else are you going to do after 15 minutes? If I have two hours to get ready, I'd be sitting there waiting.

I don't like trends They tend to make everybody look the same. For me, it's important in fashion to have individuality: take that look and own it.

I like accessories that you can add to a look to make it unique People get nervous accessorising, but there is nothing wrong with adding a belt or a pair of shoes in another colour.

Fashion should be fun It shouldn't be labelled intellectual. You cannot have a dress hanging on a wall. It's not a book, it's something to make you happy. So have fun with it.

I have worn white shirts all my life The first one I had was my school uniform. They're my security blanket; you can't go wrong. You can wear a white cotton shirt with a bold skirt and jewels, or something like that. It's snappy, fresh and seductive: I love it.

CH Carolina Herrera's new White Shirt collection is now available at CH Carolina Herrera, London SW3, tel: 020 7581 3031