I've read hundreds of "how to succeed" articles and books but the best advice I ever encountered came from the great Napoleon Hill: "Think twice before you speak, because your words and influence will plant the seed of either success or failure in the mind of another."
That's the general rule but it's easier to apply when reduced to a simple conversational trick than anybody can use immediately to become more popular and respected:
Pause a full second before responding.
This tiny change in your daily behavior reaps enormous benefits:

1. It prevents you from interrupting.

When you interrupt people, you're telling them you don't respect them. If you interrupt because you know what they're going to say, you're adding insult to injury by implying that they're boring.
By contrast, when you pause before responding, you're telling people that you care about them and their ideas. You're showing respect and will naturally get more respect in return.

2. It gives you time to focus.

Most people use the "Ready, Fire, Aim" approach to business communications. They get so caught up in the flow of the discussion that they blurt out useless or even damaging information.
However, every conversation should have a purpose, especially in business. (Otherwise why bother?). Pausing gives you time to "aim" your remarks where they'll do the most mutual good.

3. It makes you more articulate.

Many people speak in run-on sentences punctuated by verbal tics (such as "like", "uh...", and "you know") that give them time to think about what to say next. Because they're making things up on the fly, they sound inarticulate.
Pausing before you speak gives you time to collect and order your thoughts so that you can communicate more clearly in complete sentences that make sense from the start.

4. It makes you seem smarter.

Talking a blue streak without ever pausing to think makes people think of you as a motor-mouth. And nobody respects a motor-mouth, even if they're glib.
Pausing before speaking, however, leaves listeners the impression that you're a deep thinker. As a result, anything you say will likely be interpreted as words of wisdom.
Not only will this trick make you more popular and respected at work, it will also bring you closer to your family and friends. Every time you pause, you're giving a gift of love and respect. And that's a good thing in any relationship.