Habit:   Mentally review your day and then thank your beloved for some action, word, or experience. If you're getting ready together, tell her or him in that moment. If you're the first to bed, tell your partner before you retire, along with a goodnight kiss. If you're the last to bed, write it down for your spouse to find in the morning.

Purpose: We all have a negativity bias. This means that we naturally tend to notice what's going wrong in our world. This was selectively advantageous for much of human history. Our ability to scan for problems allowed us to avoid mortal danger⎯say, saber-toothed tigers lurking outside our cave⎯and thus pass on our genes. Our anxious ancestors avoided the tigers, whereas the blissed out navel-gazers became lunch, thus leaving no descendants!

We may be wired to survive but that doesn't mean we're wired to be happy. While developing a habit of appreciation might not have kept you alive on the plains of prehistoric Africa, today it will make you more happily coupled.

Habitually demonstrating gratitude for your mate's recent behavior does several things. First, your partner feels appreciated. And when your partner feels appreciated, he or she opens up to love and warmth. Second, as you focus on what in your world is going well, you begin to see more and more circumstances, actions, and sweet moments for which to be grateful.

Dealing with life's challenges is largely a matter of where you direct your attention. When you shine a flashlight on problems, often you will see more problems. But when you shine the flashlight on all the things you appreciate about your partner, you increase your own satisfaction with the relationship. Gratitude is habit forming.

Note: It is not necessary for this to be a tit-for-tat habit. Be willing to offer an appreciation with no expectations for reciprocation. View it as a gift given freely, regardless of the response.

(excerpted from "75 Habits for a Happy Marriage")