I'm rarely misunderstood if I'm given apt time to think fast enough to nail down what I want to say. If someone doesn't give me a chance to think or if I'm not expecting the conversation then I can become misunderstood as I'll end up speaking without thinking things through clearly. The only other time I advise really taking what I say with a pinch of salt and the like is when I'm hammered because then I often say stuff and can't think clearly enough for it.