Imagine feeling uncomfortable about saying something important, valuable, or beneficial, even when you know it would be best to say it. You should tell yourself, "Just say it." Think of a role model who is able to "just say it" at the right time. It might help you to imagine being that person to get yourself to "just say it."
If you have a valid reason for not saying something, don't say it. If you feel that it would be wrong to say something, don't say it. If your words will cause unnecessary distress, don't say them.
Some people find it difficult to convey positive feedback and praise. They can say to themselves, "Just say it."
Some people are not as outgoing and outspoken as they would like to be. They should tell themselves, "Just say it."
The more you say what you should say, the easier it will become for you to "just say it."
(from Rabbi Zelig Pliskin's book: "Conversations With Yourself", p.153) [Artscroll.com])