Meditation.

I listed it as one of the 10 things should you do every day to improve your life. It can boost happiness.

Via Shawn Achor’s The Happiness Advantage:

Take just five minutes each day to watch your breath go in and out. While you do so, try to remain patient. If you find your mind drifting, just slowly bring it back to focus.

Meditation takes practice, but it’s one of the most powerful happiness interventions.

Studies show that in the minutes right after meditating, we experience feelings of calm and contentment, as well as heightened awareness and empathy. And, research even shows that regular meditation can permanently rewire the brain to raise levels of happiness, lower stress, even improve immune function.