1. Learn When to Shut Up.
Yes, this is rather different from what a trained counselor or therapist might tell you, and yet I believe it is the single most important thing I've learned in 23 years of a good partnership—and what I had not learned in five years of a bad one. There are times to let the argument rest; there are times to let the big issue take a deep breath and relax. I know, I know: As a woman, I'm supposed to want to flog the argument until no one is left standing, but I've learned that the tactic is ineffective. Now, this doesn't mean you should ignore emotional pain or live a lie. But it does mean that you should not treat your relationship like a chew toy, something you sink your teeth into every time you get bored, frustrated, or need to sharpen your fangs. It might be better for everybody to go out for a nice walk.
2. Learn to Accept Differences in Expenditure—as Long as You Are Not In Debt. If You Are in Debt, Get Out of it Now.
Your partner just bought his eighth bicycle helmet? If it makes him happy, if he can afford it, and if you have room in your basement to store it, let it go. So what if he never actually rides his bike? Maybe this helmet will make him feel like he should be out there getting some exercise. Your spouse just bought a new set of dishes even though the old set was, with a few chipped and cracked exceptions, perfectly fine—not to mention that if they were good enough for your mother, shouldn't they be good enough for you? Give the old dishes to a charity shop and enjoy the first meal served on the new ones. If, however, either or both of you are in debt, you should sell the helmets, the bikes, and, if necessarily, eat food you grow in your garden off paper plates because you've also sold the dishes. Real debt and serious money worries can corrode a relationship, even one with genuine strength behind it, quicker than almost anything else.