But she did use self-affirmations—just in a more specific way. Instead of saying a generic statement, she thought about a time she felt genuinely proud of herself. It was as simple as remembering hosting a home-cooked meal for some of her friends in the area, which helped her solidify her love for intimate social gatherings. 

Another person told me it’s even making a “to done” list, writing down the things they accomplished that day rather than looking at a list of all the things yet to be checked off, making them feel affirmed in their work ethic and grateful for what they accomplished. 

So what really is self-affirmation and how does it work? 

What do you value? 

Rather than looking at a self-affirmation as a quick positive statement, as in the mirror example, look at it in terms of a “value affirmation,” which may be more effective, Dr. David Creswell, a professor of neuroscience and psychology at Carnegie Mellon University and researcher in self-affirmations, tells Fortune.

“This is about really upholding the values that you care about and to think about why they’re important to you,” he says, including the activities that help you achieve those values. 

For Creswell, being a tennis player, dad, and professor brings value to his life. Use those activities and passions to affirm the things you already love and the ways they have made you feel, even what you’re hoping to achieve with them in the future. 

“Value affirmation is an opportunity to think about why tennis is important to me and how I see it in terms of my identity,” he says. 

Get specific about what you do well and even something you’re looking toward achieving, however small, says Dr. Lauren Alexander, a psychologist at Cleveland Clinic Akron General. It can be as simple as valuing kindness, and reminding yourself of something you did that affirmed that value, she says, like reaching out to an old friend or thinking about a way you can show kindness in the future. 

How do self-affirmations work in the brain?

When you affirm a value, you activate the brain’s reward system, something Creswell studied using brain scans from people partaking in self-affirmations, specifically when affirming one’s most important value. 

“Those brain reward responses seem to be a powerful vehicle for turning down the brain’s stress alarm system,” Creswell says. 

The more routinely you affirm a value, the more you exercise the part of your brain that establishes that connection so you can believe it about yourself when you have a challenge. The practice can also help reduce rumination about upcoming challenges, Creswell says. 

In a study, Creswell found that students practicing self-affirmations through writing activities in the two weeks before a test had a lower stress response measured by stress-inducing hormones than those who did not perform the brief activities.

“We show that we can change their stress biology the night before the exam with these two writing sessions,” he says. “That affirmation activity really kind of sets into motion a whole different pattern of responses.”

When we feel anxious or stressed about something, “our perception of ourselves shrinks,” says Dr. David Hamilton, an organic chemist, kindness expert, and author of The Contagious Power of Thinking: How Your Thoughts Can Influence the World. Self-affirmations can help improve that perception, a potentially more tangible way to improve confidence. Self-affirmations looking toward the future were previously associated with improved self-processing including positive valuation, or seeing yourself in a more positive light. 

Like strengthening a muscle at the gym, it takes time to improve the thinking patterns associated with our sense of self. Neuroscientists call the brain’s ability to adapt neuroplasticity. 

“To work out a region of the brain, all you really have to do is do something or think something repetitively,” Hamilton says. 

So how can I start? 

Start small. Consider using writing as a tool and taking 10 minutes each day writing down what you’re grateful for as a way to reflect on your values. Even practicing saying things to ourselves can help. Rather than be too general, which can feel less personal, think about something relevant to your day or week. 

Beyond writing and saying things to ourselves, it can be helpful to put these affirmations into actions. If you are writing about having positive thoughts about social interactions as a way to affirm your values, consider speaking to someone new at work or introducing yourself at a local coffee shop. 

While affirmations are not a fix to managing more complex mental health struggles, they can help flex the brain and change our thinking patterns to make us more comfortable taking on a challenge and trusting our own abilities—whether that looks like solo journaling time, a “to done” list, or even remembering the warm moment of that group dinner.