If you've ever gotten relationship advice, you've probably heard plenty of don'ts. Don't nag. Don't stonewall. Don't blame. Don't leave the toilet seat up, don't squeeze the toothpaste tube from the middle, and definitely don't assume he's that into you when he's just not. Well, don't listen.

The happiest couples focus on do's, not don'ts. Rather than just steering clear of negative interactions, they actively work to build positivity into their relationships. They show what psychologists call an "approach orientation," moving toward what's good, rather than moving away from what's bad.

Traditionally, couples research has focused more on minimizing negatives (arguments, emotional distance, ) than on maximizing positives. But a new wave of research is changing all that. Positivity-oriented psychologists find that maintaining a favorable balance of positive to negative emotions helps people—and relationships—thrive. "We've already learned about all the toxic stuff that harms relationships," says psychologist Dacher Keltner, author of Born to Be Good. "There's a whole new science of how to build in good emotions."

Positivity has a way of shifting our perspective: While negative emotions shut us down, positive emotions open us up. They help us "broaden and build," argues Barbara Fredrickson, a psychologist at the University of North Carolina at Chapel Hill and author of Positivity. Positive emotions actually spur big-picture thinking, yielding benefits like keener peripheral vision and increased —not to mention better relationships.

"Finding ways to inject and lightness into a difficult situation is not merely a distraction," says Fredrickson, "It actually helps people see possibilities." Partners stuck in a "one-note song" should move towards greater positivity by seizing "micro-opportunities" to connect, she says. Positive emotion is about more than just having fun—it includes , inspiration, and curiosity.

When participants do a "loving-kindness ," a form of meditation focused on generating warm and tender feelings toward others, the quotient of positive emotions in their lives increases, which in turn boosts relationship satisfaction, Frederickson has found.

In fact, just setting more positive for your relationship can make you happier as a couple. Couples who seek to increase the good in their relationships, concentrating on sharing fun and meaningful experiences together, promoting growth and development in the relationship, and creating satisfaction and ("approach-oriented goals"), fare better than couples focused on ducking the negatives ("avoidant-oriented" goals), says Emily Impett, a researcher at UC Berkeley.

You may not always achieve all the positives you seek—but it's enough to realize that positivity is important and to set goals reflecting that. The payoff is great: more fun, more growth, better , and more sustained intimacy.

1: Be grateful.

Remembering to thank your partner seems simple, but gratitude may provide the everyday dose of spackle that keeps you glued together over the long haul. "Gratitude helps remind us of the good qualities in our partners," says Sara Algoe, a psychologist at the University of North Carolina at Chapel Hill. "It reminds people to attend to the others in their lives."

In a study of cohabitating couples, on days that one partner expressed more gratitude, the other felt more satisfied with the relationship. "We get into these routines and start taking our partners for granted," says Algoe. "But gratitude can work as a booster shot, injecting positive emotion into the relationship."

A low-quality expression of gratitude focuses on the object—"Thank you for cooking dinner, I was really hungry," explains Fredrickson. It's much better to focus on the other person: "You're such a great cook; it's so thoughtful of you to cook for me!"

"A lot of people express their appreciation in self-absorbed ways," Fredrickson says. "But when the expression of gratitude focuses on the other person, we find the other person walks around feeling better about themselves—and six months later, the relationship is stronger."

2: Poke fun at each other.

Playfulness is one of the first casualties of a busy life, says Dacher Keltner. When your life consists of nothing but working, paying bills, cleaning, and sleep, play can disappear from a relationship. "You have to keep it alive by having fun, joking around, using silly nicknames," he suggests.

You may think sincere communication is the way to handle a serious issue. But Keltner has found that couples who teased each other in the heat of a conflict felt more connected after the fact. When he staged a conflict discussion in his lab and compared couples who communicated in a direct, logical way with those who made light of the conflict, he found that couples who tease are happier and reach more peaceful resolutions.

That's because couples who can tease can use that modality to handle the tough stuff in a relationship. Even silly nicknames help turn conflicts into peaceful exchanges, Keltner says, by reminding couples to smile at each other's quirks. So if you're annoyed by a partner's long-standing habit—say, stealing the covers in the middle of the night—try teasing. Calling your partner the Blanket Monster might take the edge off your irritation while reminding your partner to share. Remember to tease in a way that's playful, not hostile; use nonverbal cues that convey you're having fun, like a silly facial expression or a change in tone.

3: Capitalize on good news.

We expect our partners to provide us with a shoulder to cry on when times are tough—but how couples behave during good times might be even more important. Partners who respond enthusiastically to each other's successes—asking questions, paying compliments, and cheering each other on—report greater relationship satisfaction over time, says Shelly Gable, a researcher at the University of California, Santa Barbara. A couple's ability to "capitalize"—that is, to celebrate each other's positive events—predicts satisfaction better than their commiseration over negative events.

When something good happens to your partner—a promotion, a compliment from a coworker, or even just a witticism that gets a big laugh—seize the opportunity to make the most of it. You don't need a major event as an excuse to break out the good china.

4: Use your illusions.

We may think putting our mates on a pedestal is unrealistic—but in fact, partners who idealize each other wind up happier. Partners in the most satisfied couples rate their mates more positively than the mates rate themselves, finds Sandra Murray, a psychologist at the University at Buffalo (SUNY) who studies positive illusions.

Similarly, when spouses perceived their partners as being nicer than their actual behavior warranted, they maintained greater long-term satisfaction than spouses who did not idealize each other as much, according to research by Paul Miller, Sylvia Niehuis, and Ted Huston at the University of Texas, Austin.

So if you value your clear-eyed judgment of others, including your partner, it may be time to ease up a little and concentrate on what you like about your mate. Looking through a soft-focus lens might help you build a genuinely rosier picture over time.

5: Find your ideal self—in your partner.

happy couples bring out the best in each other. But when partners more closely resemble each other's ideal selves, couples fare better—above and beyond the benefit to the relationship afforded by how similar you are in actuality, says Caryl Rusbult, a psychologist at the Free University of Amsterdam.

Someone who describes her ideal self as physically fit, for instance, might be happy being with a disciplined athlete; someone who longs to be more creative might thrive with an artistic partner. Rusbult calls this the "Michelangelo effect," since partners can help "sculpt" each other's best selves by affirming each other's efforts at self-improvement. The aspiring fitness buff, for example, appreciates her partner's reminders to work out.

So try listing your personal goals. Then think about the qualities you like most in your partner. Chances are, there's overlap between the self you aspire to and the aspects of your partner you appreciate most. Then recruit your partner to help you improve in the domains that matter to you. You'll not only get closer to your ideal self—you'll also feel closer to your partner.

6: Notice what's new about your partner.

Letting your partner surprise you is vital to sustaining excitement in your relationship. But in order to be surprised, you first have to pay .

The problem is that most of us get so familiar with our partners, we stop really noticing them. "But the fact that you stopped looking doesn't mean they've stopped changing," says Harvard psychologist Ellen Langer. It's only the illusion of stability, Langer says, that leads us to conclude our partners are fixed, static entities.

"You feel like you've captured who this is in your mind, so you hold them still," says Langer. "But they're actually growing and changing all the time. Once we think we know another person so well that we don't pay attention to them anymore, the person stops being seen."

So take the time to actively notice differences: Look for five things that are different from the last time you looked. These differences can be as simple as a new necktie and as profound as a shift in beliefs. Taking the time to notice—what she calls "mindful awareness"—increases our engagement with our partner.

When non-football-fans watch a game while writing down new things they notice about the players and the stadium, they become more enthusiastic about the sport, Langer found. "You develop a passion for what you're engaged in," she says.

So become engaged with your partner. Once you begin to really pay attention, you'll be amazed by what you discover.

7: Put it in writing.

For a recent Valentine's Day, Los Angeles-based film editor Stefan Grube gave his wife Julie a journal, with the idea that the couple would take turns writing to each other. "There's something great about using a pen and paper that helps us really take the time and express our feelings," says Julie. "I cannot tell you how excited I am when I see he's replaced it on our shelf and I know there's a love letter awaiting me."

Writing has a way of shoring up romantic emotions. A University of Texas study found that when participants wrote about their relationships for 20 minutes at a time for 3 days, they were more likely to be together 3 months later. They also expressed more positive emotions in instant message conversations with each other—the writing had prompted more good feelings about the relationship. So next time you think fondly of your partner, write those thoughts down.

8: Provide support in secret.

You might think showing a partner explicit support—like cooking special meals or running time-consuming errands—will shore up your connection. But overt social support carries a cost: Partners feel obligated, which leads to more stress, found Niall Bolger, a psychologist at Columbia University.

The most effective support was actually "invisible." When one partner claimed to be providing support the other partner did not report receiving, the other partner showed more improvement in mood than when receiving explicit support.

The lesson? Hidden acts of kindness brighten your mate's day, especially when he or she is going through a challenging time. So instead of making grand gestures, find subtle ways to make your partner's life easier: Stock the fridge with a favorite drink or straighten up a cluttered workspace. Being surreptitiously supportive is a good way to exercise your positivity muscle on a small scale.

9: Get back in touch.

Sure, having regular sex does wonders for relationship satisfaction and well-being. But for couples whose sex life is stalled, even just a little warm touch can make a difference.

A simple "listening touch" exercise, in which partners gently touch each other's neck, shoulders, and hands, increases , a that facilitates , and reduces partners' blood pressure and physiological stress levels, found a team of researchers from Brigham State University and the University of Utah.

"Cultivating 'body sense' awareness on one's own and with one's partner is essential, not only for a good sexual relationship but during any close encounter," says Alan Fogel, a University of Utah psychologist who helped develop the touch intervention.

In other words, you can reap the benefits of physical closeness even when you don't have the time or energy for full-blown intimacy. Just a quick hug or backrub can boost your mood—and your connection with your mate.

10: Look after yourself.

You may think the best way to improve your relationship is to focus more on your partner, but that's not always true. Investing in your own life and will pay off, too.

"If you're going through a rough patch, often the most effective thing that you can do is to lovingly remove your attention from the relationship—period," says Susan Biali, wellness coach and author of Your Prescription for Life. "Forget about what the other person is doing badly, or isn't doing, and focus on taking positive action in your own life instead."

By making your life more satisfying, you take pressure off your relationship to be your sole source of happiness. "Plus, by taking care of what you need to in your own life, you bring a more positive attitude back into the relationship," Biali says. "The other person will start to treat you differently—without you having done anything other than shift your energy into your own life." For Biali, this strategy took her relationship from "constant chaos" to happy .

Whether you choose to say thanks, sneak in some invisible support, or coin a silly nickname, a little positivity goes a long way. Small gestures matter. Expensive gifts and exotic vacations are nice, but not as meaningful in the long term as simple actions like taking the time to notice a new outfit or cheer a partner's success. Positivity expands your awareness, begetting more positivity—more noticing, more engagement, more appreciation, and more trust. Little actions help build a reservoir of goodwill that will keep your relationship replenished.

The opportunities to fill that reservoir are out there. Don't miss them.