8. Never talk when you don't have something to say. 没有主意的时候不如保持沉默

We've all known the guy who must speak in every meeting, even if he has nothing to add. (Okay, we've all known a lot of those guys.) You may think you need to contribute just to show you're involved; the rest of us know you're just talking to show you're important. And we think a lot less of you as a result. Think of words as something scarce; use them sparingly and only when they will make the most impact.