I use something like this technique. There are certain phrases from my internal monologue that I've flagged as indicators that I'm being ridiculous. When I start using phrases appropriate to the dramatic climax of a movie ("I can't do this! I should never have tried!" or "He just doesn't care, does he?") I make myself check whether the degree of drama is suited to my actual situation (parallel parking, or trying to talk to someone who's engrossed in what he's reading). If the level of drama is way too high for the actual situation, I need to laugh at myself and give it a calmer try.

I also learned while working in a domestic violence shelter that even in genuinely dramatic situations (woman arrives at the door fleeing abuser), a dramatic response still isn't helpful. At that point you need to act normally (speak softly, get her a glass of water, help her calm down) rather than heightening the drama by rushing around and generally acting as though you were in a movie.