Being impulsive causes many mistakes and errors. Doing things impulsively will cause loss, damage, and harm. Saying things impulsively will cause you to say things better left unsaid. Thinking before you speak will enable you to think of the best way to say something. Thinking before you take action will enable you to consider whether you should do something, and how to do it if you should.
The two words that will remind you to stop and think are, "Just pause." As you pause, think to yourself, "What is the wisest thing for me to say and do now?"
Practice building the association in your mind between, "Just pause," and, "What is the wisest thing for me to say and do now?" How do you build the association? It's quite easy. You just repeat these two sentences together a number of times. Repeat them with an upbeat tone of voice, or sing them with your own tune. Enjoy the process. This way you will access positive feelings when you recall this association in "real life."
(from Rabbi Zelig Pliskin's book: "Conversations With Yourself", p.150) [Artscroll.com])