Sleep. Just...Sleep.

While Rubin acknowledges the obviousness of this tip, she was still quick emphasize that if we want to get happy, we have to get. More. Sleep. "People may think they're depressed, but really, they're just exhausted! You may think that you've trained yourself to get by on five or six hours a night, but studies have shown that it's simply not true — sleep deprivation affects everyone's health in one way or another."

To find out if you're (really) getting enough sleep, ask yourself a few questions, says Rubin. "Do you wake up naturally? Do you fall asleep every time you're in a quiet place? If so, you're probably not getting enough shut-eye at night." If this describes you, try this: count back seven hours from the time that you usually set your alarm for to find your ideal bedtime, and try to hit the hay that time every night. This may not be the easiest tip, but we'd say the benefits (happiness, healthfulness, even prettier skin!) make the pursuit of zzz's more than worth it.