1. It's better to be kind and supportive of your partner than it is to be right or to get your way. Stress is so much easier to handle as a supportive team.
2. Learn how to bring out your partner's strengths rather than their weaknesses. Both are always there, but the trick is to bring out the best in each other.
3. Don't take good things your partner says or does for granted. Express appreciation for them each and every time. It only takes a few seconds.
4. Never speak to your partner in a manner that is more hostile than the tone you would use with a stranger. Partners deserve better treatment than strangers, not worse.
5. Don't take what your partner says or does personally. How a partner behaves is 95% about them and only 5% about you. People are who they are long before they become couples. Every person grows up in a unique family environment, and every partnership is therefore cross-cultural. However, NEVER side with your parent against your partner. And remember: you may not understand or like everything that your partner is or does, but you picked them, and the good and the bad are often two sides of the same coin. There are no perfect people, and if there were, even that would be annoying!
6. Everything is subjective, and short of violence, which is always wrong, disagreements are not about who is right or wrong, but just about different ways of experiencing and approaching things. Try to listen to what your partner has to say about his or her experience without arguing about whether it makes sense to feel that way. Feelings are not necessarily rational, but that doesn't change the fact that a person has them. Agree to disagree when you can't reach a consensus.
7. Speak about what would work better for you rather than criticizing your partner. Every good relationship requires censorship of hurtful words and acts that will only do harm if expressed, so practice expressing your needs in constructive ways that the other person can hear and consider. If your partner experiences you as speaking in an irritated tone, and you don't think it's true, consider this: most people are good observers of whether they are happy or sad or anxious, but terrible observers of whether they are irritable. Why that is I cannot say, but it is one of the most consistent observations that I have made in treating scores of couples. During arguments, NEVER use the "D word" [divorce] or otherwise threaten abandonment. NEVER bring up lots of old junk. Stick to the topic at hand in the present and fight clean if you need to fight.
8. Speak for yourself and about your perspective, rather than about what the other person feels or is doing wrong. Each person gets the last word on his or her own feelings and thoughts.
9. It's much easier to change your own behavior than it is to change your partner. Your own behavior is something you (at least potentially) can control. All unpleasant interactions are a dance of two people. Stop doing your part. Try more adaptive strategies instead of doing the same predictably unsuccessful things over and over again. Most arguments are highly repetitive. Don't keep hitting yourself over the head with the same old hammer.
10. After you have children, remember to regularly spend time together alone, even if it's only for brief periods of time. Let trustworthy others babysit. Remember that children grow up, and then it's just the two of you again. Also, remember to take care of yourselves individually. Getting away from children to do basic things like exercise and socialize with friends is required for survival as a sane human being. If you're depressed, anxious, or irritable, consider it your own problem and do something about it. Only you can be responsible for your inner state of mind, and no one can "make you" happy except yourself. Do avoid having angry arguments in front of children, since children, starting from a very young age, find fighting between their parents very frightening. Remember, children feel vulnerable and helpless, and view their parents dangerous when they are angry.