Plan ahead. Do you see red every time your husband runs up the credit card bill? Take time before it comes to figure out how to start a conversation with him about it, says Susan Heitler, Ph.D., coauthor of The Power of Two Workbook: Communication Skills for a Strong & Loving Marriage. If you've rehearsed a calm approach in your mind, you may not succumb to the urge to just let the issue drop.
Let your kids motivate you. Speaking up for yourself will show them how to deal with conflict constructively.
Seek expert advice. If you still find yourself squelching thoughts, pick up a self-help book, take a class about communicating with others -- or consider couples counseling.