Beware of characters who sigh often in scenes, just as you’d be wary of characters tapping their foot, rolling their eyes, and checking their watch to show impatience. They’re summaries of more complex emotions the writer is trying to get at. An actor using these gestures would be thrown off the stage or set. Why? Because they're performance clichés. And they’re no less a cliché in fiction. Give your characters gestures that are specific to who they are. I often think of Bogart’s signature gesture as Philipp Marlowe in The Big Sleep, tugging his ear as he contemplates the mean streets he walks. Twenty years later, Jean Paul Belmondo paid homage to this gesture in the film Breathless, in which he rubs a thumb along his lips as he stares at a movie poster of Bogart. Look for a gesture that is specific to your characters and it will give them a spark of originality that might just be unforgettable.