Today is Valentine's Day, which means across the world florists, jewelry shops, and restaurants are doing bumper sales. That's good news for more than these businesses. No relationship was ever made worse by roses, diamonds, or a good meal out. But it's also true that romantic gestures aren't enough to keep a couple going strong

For that you need steady relationship maintenance. Like a dental checkup or car service the necessary work to keep your bond strong isn't exactly sexy, but according to psychologist Gary W. Lewandowski Jr., it is essential. 

"Whether your relationship is already stuck in a rut, or you're trying to avoid ending up in one, most people need to focus more on what happens between 'I do' and 'I don't want to be with you anymore,'" he wrote recently on The Conversation (divorce lawyers agree with him). He went on to suggest a simple maintenance plan for any couple looking to keep their bond strong. 

1. Think of boredom as a call to action. 

The early days of love are intoxicating, but then life happens and boredom inevitably sets in. You could think of the feeling as a warning sign or sad inevitability, but instead Lewandowski urges couples to view it as a call to action. 

"Boredom serves a purpose. Like your phone indicating your battery is low, boredom is an early warning system that your relationship needs a recharge," he writes. Citing research by fellow psychologist Cheryl Harasymchuk and colleagues, Lewandowski suggests that when boredom strikes, couples should respond by planning more novelty and growth into their lives.  

Next time you start to feel in a rut with your partner, sign up for a class, book a trip to somewhere new, or try out an activity you've always wanted to explore. 

2. Never stop dating.  

You might have been married for decades, but that doesn't mean you should stop dating. Again, tackling fresh, new activities together will be most helpful in keeping the spark alive.  Lewandowski mentions fun research comparing the relationship effects of playing board games and taking an art class. Paint'n Sip beat Jenga hands down. But even tamer date nights help keep relationships strong. 

"Over the course of a month, researchers asked some couples to watch and discuss a romantic comedy such as 'When Harry Met Sally,' while others did an intense relationship workshop. Fast forward three years, and the movie watchers were less likely to have broken up," Lewandowski notes. So if you're terrible at art (or short on babysitting), just firing up Netflix together regularly is a great place to start. 

3. Count your blessings.

You know how you remember and obsess about the one negative thing that happened to you in a day, while completely forgetting the 14 good things that did? The way we overemphasize the negative is a well established fact in psychology, and Lewandowski insists this tendency seeps into relationships too. 

If you want to stay together, you need to actively work to counteract our inborn bias for the negative. "Too often, people wait for something to break before trying to fix it. Adopting a maintenance mentality can more proactively help your relationship," he writes. This maintenance can take many forms, from writing your partner a letter of gratitude to just taking a moment each day to count your blessings. Whatever approach you take, science shows it will benefit your relationship quality. 

So go buy those chocolates or make that reservation at your better half's favorite local spot. But don't think keeping your relationship going is mostly about romantic gestures. Instead, research shows it's about week-in-week-out maintenance. That's not flashy, but it is essential if you still want to be happy together decades from now.