Cruella de Vil, the fictional character and the primary villain in Dodie Smith‘s 1956 novel The Hundred and One Dalmatians, is also portrayed in all her evil glory in Disney’s 1961 animated film adaptation and subsequent live-action films. You can read up on her full history in Wikipedia.
The eyes, emphasized by extreme eye make up, are the primary expression of evil for most portraits of this kind of character. Her eyes, half closed and predatory, she usually is shown with a slight smile. Shown here is a breakdown of the fashion eye and how it works for the stylized eye of the fashion femme fatale.
I tried to imagine her as a 1950’s era fashion plate although I am sure Peta would have had a fit over that. Artists in the entertainment design industry might find the kind of stylization fashion illustrators use helpful in drawing these femme fatales.