If you don't have something to say, then don't
It's the traditional advice given young children. Don't speak just to be saying something. If you don't have something to say, then don't say anything.
But today, that advice is ignored completely. Social networking tools like Twitter now encourage people to say nothing at all, constantly. Authors are told that they have to write one more story about the popular character, even if it doesn't make plot sense, or the author has nothing more to write on that subject. (This has resulted in numerous unsatisfying stories, or contrived methods of just killing off the character so that the author can move on.) Television shows are forced to continue long after the writers have run out of good ideas, or stories to tell with those characters. Today, we even give such a name, jumping the shark. We argue about when a television show "jumped the shark".
In business even, this advice would be useful. Many people, from managers to techies feel they have to attend meetings, to speak up on them even though they have nothing of interest to say. This isn't the person who comes to the meeting to listen quietly and only speaks up when they actually have something to say. This has caused numerous meetings to get confused or go overly long.
Probably the most extreme case of following this advice was Sir Isaac Newton. As I understand, through many years in parliament, his only statement of record was a point of order, requesting the windows be opened on a particularly warm day.