If it's a sultry scene with a starlet, the lighting moves to an overhead butterfly pattern with some diffusion to give her a soft dreamy look. When you want a man to have a rugged chiseled look, use hard edged short lighting. For a funnyman an even broad light makes him look brighter. Sometimes one simple scene between two lovers can almost be a master class in lighting for your mood.
In addition to the movies mentioned above, check out the lighting in The Maltese Falcon and Casablanca.