If you are in (or even want to be in) a long-term relationship, I think it’s probably safe to assume you’d ideally like it to be a happy one. But as anyone who has ever been in a relationship knows, staying happy in one—especially over a long period of time—is often easier said than done.

Early on in our love lives, we tend to assume that finding love and establishing a happy, secure relationship is the hard part. This is not to say it’s not—trust me, as a single dater myself, I am sympathetic to the plight of those weathering the modern dating landscape! But while it’s only natural that exhausted daters would see finding and settling into a steady, stable relationship as a finish line that guarantees a happily ever after, the potentially annoying truth is that maintaining that happiness can be just as difficult as finding it.

“Long-term relationships can be challenging,” says Leanna Stockard, a therapist at LifeStance Health. “But they can also be extremely fulfilling.”

This isn’t exactly news, of course. We’ve all heard that “relationships take work.” But what does that work really entail? While there’s no exact science to long-lasting relationship success, there are certain relationship-strengthening habits, behaviors, and mindsets that happy, long-term couples tend to share. Below experts, share their top five tips for couples seeking lasting happiness in long-term partnerships.

1. Communicate to Understand, Not Just to Make a Point

As a relationship progresses over time, “couples may lose sight of the importance of effective communication,” says Stockard. “Whether you have been in a relationship for one month, one year, or ten years, it is imperative that you communicate openly, honestly, and directly about your thoughts and feelings.”

Relationship coach Jacquie Del Rosario, PhD, adds that the key to effective communication is to avoid using it as a tactic to prove yourself right in an argument. “Learn to communicate to understand and not to win points,” she says. “In doing so, couples use communication to understand each other’s needs and feelings instead of trying to win a debate. Strong couples regularly express their thoughts and feelings honestly, which fosters understanding and emotional connection.”

2. Stay Curious

“Stay endlessly interested and curious in your partner,” advises relationship expert Carolina Pataky, PhD, founder of South Florida’s Love Discovery Institute. “No matter how long you’ve been together, don’t fall into the trap of thinking you know them inside out. People shift, grow, and surprise us. The couples who last are the ones who keep asking, ‘Who are you today?’ They listen closely, stay curious, and discover new layers in each other again and again.”

3. Pay Attention

“Attention is the most basic form of love,” says James Córdova, PhD, professor of psychology at Clark University and author of The Mindful Path to Intimacy. “Whatever we pay attention to grows and strengthens.”

In a long-term relationship, it’s easy to take your partner for granted and gradually start to focus your attention elsewhere. But simply paying attention to your partner and your relationship is a seemingly simple but hugely important part of maintaining a happy, healthy connection.

4. Continue to Set Goals

Again, getting married or into a long-term relationship isn’t the finish line. Stockard says it’s important for partners to keep setting and pursuing goals together, both in terms of their relationship itself as well as their broader life together as a couple. “It is very important to continue to check in with your partner on your shared goals and to discuss if anything has changed at any point in the relationship,” says Stockard. “This will help partners continue to create a shared meaning in the relationship and work together on setting new goals.”

5. Grow Together, Not Apart

We often hear about partners simply “growing apart.” And while this can happen, it’s not inevitable. One way to avoid growing apart is to actively work towards growing together, says Pataky.

“Strong couples don’t just share a home or a history—they share a vision. Whether it’s supporting each other’s dreams, setting goals as a team, or simply checking in about where life is heading, they keep moving in the same direction,” says Pataky. “Growth is inevitable, but happy couples make sure it’s growth with each other, not away from each other.”