Loulou was a fashion muse and designer for accessories and jewelry. She was associated with Yvs Saint Laurent. Eventually, she launched her own business and left St. Laurent. She began designing ready-to-wear costume jewelry for customers everywhere. Her jewelry is influenced by classic styles and vibrancy. 

Lou Lou life dates of 4 May 1948 – 5 November 2011. She was a fashion muse and designer of fashion, accessories and jewellery associated with Yves Saint Laurent. 

La Falaise was born in England and moved to NYC in the late 1960s, where she briefly modelled for American Vogue before turning to designing printed fabrics for Halston. Late in the decade she worked as a junior editor at the British society magazine Queen, during which time she met Saint Laurent. Eventually, she moved to Paris, where she joined his haute-couture firm in 1972. Responding to a description of her as a Saint Laurent muse in 2010, La Falaise responded, “For me, a muse is someone who looks glamorous but is quite passive, whereas I was very hard-working. I worked from 9am to sometimes 9pm, or even 2am. I certainly wasn't passive.”

"Her official task was to bring her eccentric style to accessories and jewellery, and she duly came up with often-chunky designs incorporating large colourful stones, enamel work or rock crystal". La Falaise also inspired Saint Laurent with her inventive wardrobe: "one week she was Desdemona in purple velvet flares and a crown of flowers, the next Marlene [Dietrich] with plucked crescent-shaped eyebrows". In 2002, when Saint Laurent retired, La Falaise began producing her own clothing and jewellery designs.

She also designed cloisonné boxes and porcelain vases for Asiatides, as well as jewellery for the boutique of the Majorelle Gardens in Marrakech, Morocco.

After more than three decades designing jewellery and accessories for Saint Laurent, La Falaise launched her own fashion business, designing ready-to-wear, costume jewellery, and accessories, which were retailed in the U.S. as well as two Loulou de La Falaise shops in Paris.

She sold simplified versions of her jewellery designs in a line created for the HSN and created costume jewellery for Oscar de la Renta. She operated two of her own shops in Paris, one of which was designed by her brother, Alexis

La Falaise was allegedly baptised not with holy water but with Shocking, the scent by fashion designer Elsa Schiaparelli, her mother's employer.