Marie Helvin:

I first met Yves at his Paris atelier in rue Spontini, and he booked me straight away. I think I reminded him of a model at Dior who was Eurasian, and he was intrigued that I was from Hawaii. For him it was like I was from Mars – he didn't really travel that much apart from between London, Paris and Morocco. I think he once went to Tokyo, too, but he wasn't a big traveller.

It's often said that he introduced non-white models to the catwalk, but it's something of a misconception that no one was using black and Eurasian models before Yves – there were some designers, such as Givenchy and Ungaro, who only used black models. But Yves used a combination of different girls. He worked a lot with one model called Mounia, who was from Martinique. She was so difficult! A lot of people didn't take to her, but he adored her and allowed her to behave as badly as she liked. So he used Mounia and Iman and me, and then, later on, Jerry Hall, too. He liked the fact that we all had a different take on fashion.

During fittings he would always ask us: "Would you wear it like this? Would you wear it with jeans? A skirt?" I think he was interested in our very different backgrounds. He came from Algiers so had an unusual kind of childhood himself.

His early shows [at the start of the Sixties] were tiny, with only about 14 people watching. I remember that Lauren Bacall was at one of them and said, "Hey, you, come over here!", because she wanted to feel the fabric of my dress. I didn't know what I was supposed to do, but then I thought, hey, this is Lauren Bacall, so I let her touch the dress anyway.

For shows and campaigns, Yves had two favourite looks for me: either hair scraped back, which I hated because I thought I looked like Jiminy Cricket; or really big and teased out, which was a nightmare to untangle, but in those days no one cared about a model's hair. You just did what you were told to do.

I always liked Yves. He was fun. We moved in the same circles in the Seventies: I was hanging out in Paris with a wild crowd, so was he. He liked being around Kenzo and [model and designer] Loulou de la Falaise. He hung out at the nightclub Le Sept, he drank, he fooled around. It was a wild time, and there were drugs and drink. He loved being with young people, whether gorgeous men or women. He loved youth.

He was such a generous man, and I was given a lot of the clothes that I modelled. I've given a lot away to auction because I can't wear them any more, but if I think back to my favourite photos, I'm always wearing YSL.

Alexander McQueen

Genius. Pure genius. Yves Saint Laurent is the reason why am I in fashion. I remember, in the Eighties, when I first saw his Picasso collection with the doves, the sense of drama, the sense of proportion – it was incredible. Then there's the tuxedo [for women]. Yes, he might not have been the first person to do that, but he made it what it is today. He has always been a great influence on my work.

Naomi Campbell

I met him when I was 16, when he first used me in his shows. He was so sweet. He got me to put on a tuxedo and I came out, and he said, right, no pants! And I took them off, and he said that's it. And that was it. He was extremely kind to me. He was quite poorly, and the people around him said I shouldn't talk to him, but I did. He had a twinkle in his eye. I think he was the first designer to put women of colour on the catwalks, and I'm so grateful to him for that, for giving us a chance to be there.Every other designer has been inspired by him in some way. And I still wear my YSL, in fact I pulled out one of my old tuxedos last week. It's timeless.

Diane Von Furstenberg

Yves Saint Laurent was the most important designer of the 20th century. He transformed the way that women looked and felt. He was an artist, a visionary who created the modern woman. As a woman, he made me feel the way I wanted to feel, powerful and feminine. As a designer, he will always be a source of inspiration. As a friend, I will miss his wit and his mischief.

Giorgio Armani

I don't want to remember Yves Saint Laurent just as the foremost and truest designer of our time. I will always remember him from a private visit that I made to his museum-like home in Marrakech 20 years ago. I arrived with my sister in a run-down minibus wearing shorts and a T-shirt which I could see immediately made him feel somewhat perplexed as he stepped out to greet us in a most elegant pinstriped double-breasted suit. After just half an hour's conversation, however, he was talking to me like you would speak to an old friend. On saying our goodbyes, he urged me to return to see him again soon.

Paul Smith

It's difficult to define why Yves was so important to me, but I think it was because he was so modern in every way, especially at the beginning of his career. His social life was all about people doing amazing things, and so everything that surrounded him was of the minute, too. The clothes were very much about modern women, especially the "Smoking" trouser suit, which was revolutionary. My wife, Pauline, and I were privileged enough to go to his couture shows in the late Sixties and early Seventies. Back then, couture was shown in the salon of the designer. The most amazing show we saw was his homage to the Vietnam War. The collection was all black and, when the model opened her "Smoking" jacket she revealed a see-through silk chiffon blouse and bare skin, which was greeted with a gasp. My wife has one of the last couture "Smoking" suits made before Yves retired. It is stunning.

Vivienne Westwood

He pushed his talent to the limit. He worked so hard, even though it looked so simple: [his work] was flawless, he never failed to enhance the beauty of women.