An expert reveals the 3 traits of every successful relationship

What's the secret to making a relationship last for years? It all comes down to things you do every day. 

Psychologist and life coach Nikki Martinez, Psy.D, LCPC, told INSIDER that building successful relationships takes three key traits — and each one of them requires small but meaningful daily commitments from each partner.

Ready for the long haul? Here's what your relationship needs to have: 

1. Good communication

This one's no surprise: Open dialogue is the bedrock of good relationships. But if you and your partner are having a little trouble in the communication department, you're definitely not alone:

"[For] every couple that’s ever come to me in therapy, when I ask, 'What are your problems?' They say, 'Communication.' Every single one of them," Martinez said. 

There are a few ways to get better at communication. One is simply being a good listener. "Have an agreement that you will completely hear the other person out before you say what you have to say," Martinez said. "You don’t have to agree with what they’re saying, you just listen to their point of view and try to understand it."

Next, remember to look beyond the words your partner is saying.

We communicate the bulk of our emotions via tone of voice, gestures, and body language — not the actual words coming out of our mouths, Martinez said. (If you've ever said "I'm fine" and not meant it in the slightest, you know exactly what she's talking about.) The couples in lasting relationships tend to be better at noticing these nonverbal cues, she added.

2. A total ban on mind-reading

"So many couples make these assumptions about what the other person is thinking, what they’re going to do, what they’re going to say, how they’re going to react," Martinez said. "They’ve already played it all out in their mind."

The problem with this habit (Martinez calls it "mind reading") is that it hampers communication. We get so caught up in imagining how our partner will react to a certain question or confession or suggestion that we forget to actually talk to them about it. The worst part: We usually read our partners' minds incorrectly. 

 "I swear, like, 95% percent of the time, they’re wrong about what the person would have said, how they would have reacted, what they would have done," Martinez said. "It’s sort of like we expect the worst possible reaction."

So keep the mind reading to a minimum and keep talk openly with your partner, even when it comes to prickly topics. Their reaction likely won't be as bad as you've imagined. 

3. Frequent gratitude

When couples on the rocks come to Martinez for help, she makes them commit to a simple exercise: "Every day, they have to tell their partner something they appreciate about them. I don’t care if they leave a note, say it, send an email, text it."

Martinez has found that, at first, many couples dismiss the practice as cheesy. "Then they come back to me and they loved it," she said. "The majority of the time, it’s something they want to keep doing."

There's a simple reason it works: It's easier to remember what it is you love about your partner when you make a habit of pointing out their best qualities every day.