The How of Happiness by Sonja Lyubomirsky

Lyubomirsky provides the following twelve-fold path to happiness:

  1. Express Gratitude
  2. Cultivate Optimism
  3. Avoid Overthinking and Social Comparison
  4. Practice Acts of Kindness
  5. Nurture Relationships
  6. Develop Strategies for Coping
  7. Learn to Forgive
  8. Increase Flow (Csikszentmihalyi) Experiences
  9. Savor Life's Joys
  10. Commit to Your Goals
  11. Practice Religion and Spirituality
  12. Take Care of Your Body

These tactics appear more effective when used daily and when the exact thing done is varied.