He worked with hundreds of A-list celebrities like Cher, Janet Jackson, Tina Turner, Gwyneth Paltrow, Courtney Love and Vanessa L. Williams. He became a highly in-demand makeup artist, often acquiring $10,000 per session for photo shoots or award shows.
As a published author (The Art of Makeup, Making Faces, and Face Forward), he was fond of taking celebrities (and various other men & women, including his mother) and using makeup and costume (and sometimes prosthetics) to make them look like other celebrities, or like other people entirely. He transformed Tori Amos into Mary Queen of Scots, Celine Dion into Maria Callas, Liza Minnelli into Marilyn Monroe, Christina Ricci into Édith Piaf, Hilary Swank into Raquel Welch, Winona Ryder into Elizabeth Taylor, Tionne "T-Boz" Watkins into Josephine Baker and Martha Stewart into Veronica Lake, among others.
He made an appearance in an episode of Sex and the City called "The Real Me" (Season 4, Episode 2) as himself being make-up artist to Carrie Bradshaw.
In September 2001, Aucoin was diagnosed with a rare pituitary tumor. He had been suffering from acromegaly resulting from the tumor for much of his life, but it had gone undiagnosed. He died in May 7, 2002 of kidney and liver failure due to Tylenol toxicity, caused by an addiction to prescription painkillers used to treat the extreme pain from his condition.