The fledgling starlet Audrey Hepburn was convinced the simple, elegant designs of Givenchy would suit her character in Sabrina. She reached out, but Roman Holiday had not yet been released, and the up-and-coming designer confused her with the better-known Katharine Hepburn. Upon discovering his mistake, he refused her request, and only a charm offensive by Audrey brought him around. As the Times notes, it only took one dinner for Givenchy to be smitten, and they began a lifelong collaboration. See: When Audrey Met Hubert.
It was not the first such incident for Head. When she first applied at Paramount, she admitted to the studio's costume chief, Howard Greer, that she presented fraudulent examples of her work. He hired her anyway, and, notwithstanding this dishonorable beginning, it worked out well for all involved. See Designing Male, A Nebraska Farm Boy's Adventures in Hollywood and with the International Set.
The young Hubert de Givenchy got his start in fashion working for Elsa Schiaparelli after World War II. Her heyday was a decade in the past. She had lost that special alchemy that made her the sensation of the 1930s, and her fashion house suffered. Once, the young Hubert "was taken aback to find a little girl's dress that used snakes as its embroidery motif," which he discreetly ordered removed without Schiaparelli's knowledge. That does not mean Schiap was unaware of his talent. When he departed to start his own house in 1951, she noted sardonically, "You will bankrupt me."