8. Be interested. Shared values and interests are important in a long-term relationship, though you can't possibly have the exact same taste as your partner. But be interested. Support your partner's hobbies, at the very least, by trying to know what he or she gets out of them. Don't dismiss them as a waste of time, and don't try to replace them. You can't be the only source of someone's happiness.
9. Say "yes" more than "no." Everyone knows that it's important to set a positive tone at the beginning of a relationship. Don't stop making that effort just because you're comfortable. Accommodate your partner when you can, even if it's something as simple as agreeing to watch the movie he wants to see. Doesn't he deserve it even more after proving himself over time?
10. Pursue new experiences together. In the YourTango Irresistible You survey, respondents ranked "trying new things together" as the #1 way to stave off complacency in a long-term relationship. Novelty rules—and not just in the bedroom. Try new activities, foods, music, etc. as a couple. You'll "meet" new versions of each other, no matter how long you've been together. 18 Ways To Beat Complacency In A Long-Term Relationship