Here are the key research-based principles for turning gratitude into a lasting habit, drawing from the GGSC’s new website, Greater Good in Action.

Over the past two decades, much of the research on happiness can be boiled down to one main prescription: give thanks. Across hundreds of studies, practicing gratitude has been found to increasepositive emotions, reduce the risk of depression, heighten relationship satisfaction, and increase resilience in the face of stressful life events, among other benefits.

The problem is, gratitude doesn’t always come naturally. The negatives in our lives—the disappointments, resentments, and fears—sometimes occupy more of our attention than the positives.

But Robert Emmons, a leading scientific expert on gratitude, argues that intentionally developing a grateful outlook helps us both recognize good things in our lives and realize that many of these good things are “gifts” that we have been fortunate to receive. By making gratitude a habit, we can begin to change the emotional tone of our lives, creating more space for joy and connection with others.

Fortunately, researchers have identified a number of practices for cultivating gratitude. Many of them are collected on the Greater Good Science Center’s new website, Greater Good in Action (GGIA), which features the top research-based exercises for fostering happiness, kindness, connection, and resilience. Here I highlight GGIA’s gratitude practices, which can be divided into four main categories.

1. Count your blessings

Some days it feels like everything is going wrong. But often, even on bad days, good things happen, too—we’re just less likely to notice them.

That’s where the Three Good Things practice comes in. This practice involves spending 5 to 10 minutes at the end of each day writing in detail about three things that went well that day, large or small, and also describing why you think they happened. A 2005 study led by Martin Seligman, founder of the Positive Psychology Center at the University of Pennsylvania, found that completing this exercise every day for one week led to increases in happiness that persisted for six months.

This simple practice is effective because it not only helps you remember and appreciate good things that happened in the past; it can also teach you to notice and savor positive events as they happen in the moment, and remember them more vividly later on. By reflecting on the sources of these good things, the idea is that you start to see a broader ecosystem of goodness around you rather than assuming that the universe is conspiring against you.

Similar to Three Good Things is keeping a Gratitude Journal, which involves writing down up to five things for which you are grateful once a week and reflecting on what these things mean to you. For this practice, you can expand the scope of your gratitude beyond good things that happened that day and consider positive events from your past and even those coming up in the future. The Gratitude Journal is especially effective when you focus on specific people you’re grateful to have—or have had—in your life.

2. Mental subtraction

In the words of Joni Mitchell, “you don’t know what you’ve got till its gone.” But sometimes just imagining that something is gone is enough to make you appreciate what you’ve got.

One way to do that is to engage in the Mental Subtraction of Positive Events practice, which involves considering the many ways in which important, positive events in your life—such as a job opportunity or educational achievement—could have never taken place, and then reflecting on what your life would be like without them.

A series of 2008 studies led by Minkyung Koo found that completing a 15-minute mental subtraction writing exercise led to increases in happiness and gratitude.

Mental subtraction can counteract the tendency to take positive events for granted and see them as inevitable; instead, it helps you recognize how fortunate you are that things transpired as they did.

One variation on this practice is Mental Subtraction of Relationships, which is similar to Mental Subtraction of Positive Events but involves focusing specifically on important relationships, such as close friends or romantic partners. Although it may be painful to imagine your life without someone you care about, doing so once in a while can serve as a reminder not to take that person for granted and may improve your relationship as a result.

3. Savor

Ever notice that the first bite of cake is usually the best? We have a tendency to adapt to pleasurable things—a phenomenon called “hedonic adaptation”—and appreciate them less and less over time. But we can interrupt this process by trying the Give it Up practice, which requires temporarily giving up pleasurable activities and then coming back to them later, this time with greater anticipation and excitement.

A 2013 study conducted by Jordi Quoidbach and Elizabeth Dunn found that abstaining from a pleasurable activity for a week (in this case, eating chocolate) led people to derive greater pleasure from it and feel greater appreciation for it when they eventually indulged in it again.

The goal of this practice is not only to experience more pleasure but to recognize how we take lots of pleasures for granted, and to try to savor them more. We often assume that more is better—that the greatest enjoyment should come from abundance and indulgence—but research suggests that some degree of scarcity and restraint is more conducive to happiness.

But abstaining from the pleasures in your life isn’t the only way to help you savor them. Instead, you can try taking a Savoring Walk.

In the age of smartphones, it’s a common experience to walk down the street with your eyes glued to your screen, unaware of your surroundings. But even without a phone in hand, you may simply be distracted or in a rush, and as a result you may miss opportunities to take in some things that can make you feel good—beautiful or awe-inspiring scenery, acts of kindness between people, adorable children.

The Savoring Walk involves walking for 20 minutes by yourself once a week, ideally taking a different route each time, paying close attention to as many positive sights, sounds, smells, or other sensations as you can. Research by Fred Bryant and Joseph Veroff has found that taking this kind of stroll led to an increase in happiness one week later.

In addition to making you feel good, becoming more attuned to your surroundings can also give you more opportunities to connect with other people, even if it’s just to share a smile.

4. Say “thank you”

Gratitude can be especially powerful when it’s expressed to others. Small gestures of appreciation, such as thank you notes, can make a difference, but there are some things that deserve more than a fleeting “thanks!”

If there is anyone in your life to whom you feel you’ve never properly expressed your gratitude, writing a thoughtful, detailedGratitude Letter is a great way to increase your own feelings of gratitude and happiness while also making the other person feel appreciated and valued; it may also deepen your relationship with them.

The 2005 study led by Martin Seligman described above also tested the effects of writing and delivering a gratitude letter, finding that, of the five different practices that the researchers tested, this practice had the greatest positive impact on happiness one month later. Those who delivered and read the letter to the recipient in person, rather than just mailing it, reaped the greatest benefits.

It’s important to note, though, that six months after writing and delivering their Gratitude Letter, participants’ happiness levels had dropped back down to where they were before the visit. This finding reminds us that no single activity is a panacea that can permanently alter happiness levels after just one attempt. Instead, gratitude practices and other happiness-inducing activities need to be practiced regularly over time, ideally with some variety to avoid hedonic adaptation.

And because not every practice will feel right for everyone, it’s worth trying out as many practices as you can to find the ones that work best for you. The gratitude practices you’ll find on Greater Good in Action are as reliable a place to start as any.