Maybe you'd like a romantic evening out with your partner on a regular basis. (Who wouldn't?) Ask for it! And be very specific about what would please you. You'll be surprised how willing your partner will be to help make it happen once you request it. (If you don't believe me, just try it. What do you have to lose?) Even if the two of you just go for a drive together to look at the stars on a warm summer night, you'll be cultivating more joy.
Some other ideas you might put on your list include the following: going to the movies more often, hiking or taking a very long walk once a month, finally learning how to play a musical instrument, calling an old friend you haven't talked to in a long time but think of often, enrolling in an adult evening class, joining a book club, taking up a sport, or orchestrating a monthly girlfriends' lunch or dinner.