HOLLYWOOD’S trashy starlets could save themselves from further disgrace by following in the footsteps of Audrey Hepburn. That’s the word from Pamela Keogh, who argues in her new book “What Would Audrey Do?” that the beloved Oscar-winning actress avoided scandal by always acting with perfect style and grace in public and private. “In an era fraught with selfishness, flamboyance, and sensational headlines, Audrey is precisely what the world needs now,” Keogh notes, adding, “Audrey never had to worry about embarrassing items showing up on Page Six.”