Which actors and actresses are the most selective over their film roles?

To find out how to do the job, we talked to two veteran casting directors: Ellen Lewis, who has cast such movies as Forrest Gump, The Devil Wears Prada, and every Martin Scorsese movie since Goodfellas; and Lora Kennedy, executive vice-president of feature casting at Warner Bros., whose extensive credits include Argo and Man of Steel.