Lesson 1. If you knew that by speaking impulsively you would lose a large sum of money, you would be very careful to avoid saying anything impulsively. The cure for impulsive speech is taking two or three seconds to think about whether or not you should say what you are about to say.
Lesson 2 Deprecatory statements that would normally be permitted under certain circumstances (i.e. you have a beneficial and constructive intentions, are forbidden to be said if the listener will mistakenly think that you are speaking lashon hora. That would be considered avak lashon hora (a tinge of lashon hora).