Loulou de la Falaise obituary

The way Loulou de la Falaise told it, she had been baptised by her mother with a dab of the Schiaparelli perfume Shocking in lieu of water; or even bathed in the scent at birth. That might not have been literally true – Loulou was born in severely austere postwar Britain (in Sussex), to which her mother, the bohemian Maxime de la Falaise, had returned briefly from Paris. But Maxime, who knew Elsa Schiaparelli and later modelled for her house, certainly wanted her Anglo-Irish-French daughter to grow up fashionable and a free spirit. Which she did: Loulou, who has died aged 63 after a long illness, was a Parisian landmark for more than 40 years, her slap-happy style – clacking, clanking and chinking with the jewellery she designed – much-imitated, but never equalled.

For much of that time she was fixer, friend and supportive shoulder to the couturier Yves Saint Laurent; she did not much care for the term "muse". Muses swanned about being inspirational, while Loulou nannied Saint Laurent, led him astray and put in years of graft in his, and later her own, fashion business. She deserved more than "muse".

Maxime was Anglo-Irish, married to Comte Alain de la Falaise just long enough to produce Loulou and her brother, Alexis, before a most unamicable divorce. On the basis of her extramarital amours, a French court considered Maxime to be so unexemplary a mother that Loulou and Alexis were consigned to foster care. Maxime had to apply to the law to regain custody, whereupon she sent Loulou off to boarding schools in Sussex (expelled for inserting slugs in classmates' shoes); in Gstaad, Switzerland (expelled for secretly keeping a forbidden St Bernard in the chalet); and in New York (expelled again).

Maxime was encountering the New York scene at the time of the last expulsion, and Loulou did not need looking after once the editor of American Vogue, Diana Vreeland, discovered her interminable legs, red-blonde hair and gypsy style, and had her model for Richard Avedon and Irving Penn. Actual posing, as opposed to being snapped at a party, bored her, so Loulou fled to London, where she worked for Queen magazine, and married, aged 18, the art historian and Irish aristocrat Desmond FitzGerald, Knight of Glin, though Maxime warned her that she would be more at home with the tinkers than in his castle.

Accounts, including her own, vary of her first meeting with Saint Laurent, in 1968: the most romantic locates it in Carnaby Street ("The younger you were in London then, the more authority you had," she recalled), the most reliable at a tea party. Wherever it was, she said: "We hit it off straight away because he had a very silly sense of humour. We got into a fit of giggles." On the advice of his partner, Pierre Bergé, Saint Laurent had gone into ready-to-wear and opened a prêt-à-porter boutique, Rive Gauche. When he opened a sequel in London, in 1969, he was flanked by the woman he called his "twin sister", Betty Catroux, and by Loulou, both dressed by him to emphasise their independent shoulders and bangle-shaking wrists.

Loulou was then 21, a divorcee on the razzle in London and in New York with her mother's mates among Andy Warhol's Factory crowd, designing fabrics for Halston, hanging out with Schiaparelli's granddaughters, Marisa and Berry Berenson. (Loulou claimed that she and Berry had discovered Robert Mapplethorpe as a painter, before the photographs.) Loulou was wild, a mixer of haut vintage and cheap ethnic, happy to splurge unexpected cash earnings of $1,000 on orange leather fringed hotpants, and then dance them to shreds.

Saint Laurent loved her style, boldness and wit. When his harsh, tarty collection of 1971 was loathed on and off the catwalk, he sent her its kelly-green-dyed fox fur coats as gifts, and she wore them blithely. The next year, he invited her to Paris to work for him, role unspecified. The city intimidated her and, wanting to pass for a Parisienne, she arrived at his atelier subdued in an old grey uniform skirt: "He had told everyone his eccentric friend was coming, then I turned up looking like a 15–year–old from a strict boarding school."

She soon clicked with the staff, and also clunked and clattered, as she wore the many accessories she chose to work on – hundreds of pieces of jewellery a year, of "semi-precious or even quarter-precious" stones, mad materials given her "wonky twist" – plus a magpie collection of folkloric boots, shawls, turbans, a complete Ballets Russes production. "Her presence at my side is a dream," said Saint Laurent, and he hosted and designed her second wedding (gown included), in 1977, to Thadée Klossowski de Rola, the son of the painter Balthus.

That, and their Angels and Demons celebratory party, defined Saint Laurent's zenith of success. She had been wild with Saint Laurent beyond the clothes: too much drink, too many substances in Marrakech. Klossowski said that it was Loulou who demonstrated to Saint Laurent how to get a hit from eating rather than smoking hash. Yet her sense of self-presentation encouraged her self-preservation. She didn't self-destruct in the 80s, unlike many in the Saint Laurent entourage, and for the next 20 years she was a disciplinarian of his house, more energetic as he grew more languid, more determined to edit his collections even as he reprised his greatest hits. In the many images of their collaboration, she proposes, unrolling the textiles, cackling with glee, and he disposes, wan at his desk. In his later, fragile years, there was so much of her in the YSL collections that employees nicknamed the line "Yves Saint Loulou". She never endorsed minimalism: "I don't like black, you wear black when you're miserable."

His retirement in 2002 was a liberation, a chance to sell her own style, so thrown together at the last minute that her outfit might depend on what happened to be away at the cleaners. That level of instinctiveness needs proper tailored jackets, pants and knitwear that establish the silhouette, and she produced those as under her own label, for seven seasons from 2003. She wasn't a natural shopkeeper ("I am the worst sales person in the world. I always end up telling people, 'You don't need anything'") but she did open a Parisian boutique, La Maison de Loulou: "The first time Yves came he said, 'It has the blessing of Moujik [his bulldog],' and then the dog peed all over the wall."

Her clientele was limited; only sophisticated customers with troves of accessories from family inheritance, fleamarkets and worldwide souvenir shopping could perceive the full potential (though we are all accessory-wearers now, and combiners of high and low). As for her  own accumulations, she didn't give away "anything that I've either had a really good time in, or is a collector's item", but she did hand them down – her daughter Anna is the fourth generation to wear grandmother's Schiaps: "They do sometimes turn into a pile of dust, but that's a tribute to a good life."

Her Left Bank apartment – where else? – and Normandy house were likewise patchworked from global finds and family memories, and she gardened addictively, taking off her jewels lest they get caught in the plants. When recession closed her ready-to-wear business, Loulou continued to design jewellery, returning from a trip to New York with empty bags as the Bergdorf Goodman store requisitioned even her personal pieces.

In the end, she was reconciled to the concept, if not the word, muse: "I didn't see it as someone who worked as hard as I did. But now that Saint Laurent is part of history, it makes me a part of history, so, yes, finally it's not such a bad thing to have been a muse."

Klossowski and Anna, their daughter, survive her.

Louise Vava Lucia Henriette le Bailly de la Falaise, accessories designer, born 4 May 1948; died 5 November 2011

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