You'll never know from day to day, which ones you'll have to eat. The thought went through my mind that one's refrigerator is the perfect place to keep this reminder. Just as we need to be careful about what we eat, regarding both keeping kosher and health, so too, we need to be careful about how we speak, regarding both kosher speech and the health of one's marriage. Every statement you make can be phrased in many ways. Choose positive ways to word things.
Marriage is a great opportunity to learn tact.
Tact is when you say your position in a way that is sensitive to the feelings of the person to whom you are talking. Speaking without tact can be a violation of the Torah prohibition against hurting others with words. That's totally stupid. Do everything you can not to embarrass your spouse or put him or her on the spot. There is no need to point out every single error and mistake.