I recently had the opportunity to read a helpful book,
The How of Happiness by Sonja Lyubomirsky.
The author sets forth twelve "Happiness Enhancing Strategies". The reader is encouraged to adopt the handful of those that best suit his/her personality and situation. They are
(1) Counting your blessings: Expressing gratitude for what you have (either privately – through contemplation or journaling – or to a close other) or conveying your appreciation to one or more individuals whom you’ve never properly thanked. (CHAP 4)
(2) Cultivating optimism: Keeping a journal in which you imagine and write about the best possible future for yourself, or practicing to look at the bright side of every situation. (CHAP 4)
(3) Avoiding overthinking and social comparison: Using strategies (such as distraction) to cut down on how often you dwell on your problems and compare yourself to others. (CHAP 4)
(4) Practicing acts of kindness: Doing good things for others, whether friends or strangers, either directly or anonymously, either spontaneously or planned. (CHAP 5)
(5) Nurturing Relationships: Picking a relationship in need of strengthening, and investing time and energy in healing, cultivating, affirming, and enjoying it. (CHAP 5)
(6) Doing more activities that truly engage you: Increasing the number of experiences at home and work in which you “lose” yourself, which are challenging and absorbing. (CHAP 7)
(7) Replaying and savoring life’s joys: Paying close attention, taking delight, and going over life’s momentary pleasures and wonders – through thinking, writing, drawing, or sharing with another. (CHAP 7)
(8) Committing to your goals: Picking one, two, or three significant goals that are meaningful to you and devoting time and effort to pursuing them. (CHAP 8)
(9) Developing strategies for coping: Practicing ways to endure or surmount a recent stress, hardship, or trauma. (CHAP 6)
(10) Learning to forgive: Keeping a journal or writing a letter in which you work on letting go of anger and resentment towards one or more individuals who have hurt or wronged you. (CHAP 6)
(11) Practicing religion and spirituality: Becoming more involved in your church, temple, or mosque, or reading and pondering spiritually-themed books. (CHAP 9)
(12) Taking care of your body: Engaging in physical activity, meditating, and smiling and laughing. (CHAP 9).
I learned a few things from this book, though it's emphasis on happiness "techniques" was, for some areas, problematic for me. For example, developing a "strategy" for acts of kindness in order to enhance one's own happiness didn't sit well with me.
That being said, I am better off for having read it. First, I realized that I have a tendency to rethink and overthink things. The solution is to learn to "let go", and trust God in love and submission. Second, I am learning to get "into" what I'm doing now and live with God "here", rather than spend so much time regretting the past or fretting over the future. Third, I was reminded of the value of relationships: with God, with my wife and with my dear friends. Fourth, I have come to realize that most of my unhappiness is self-inflicted by neglect of my relationship with God.
I'd like to make clear that it does not appear to be the author's view, and it is certainly not mine, that the ultimate purpose of life is happiness. In the Christian understanding, sin is a neurosis and abiding joy is found, ultimately in repentance and victory over all that is not of God. As the Sermon on the Mount makes clear, the happy people in this world are the virtuous.
Still, happiness is a health issue, falling under the subcategory of mental health. I read it as I read books on other important health topics such as running, nutrition, running, sleep, running, weight-lifting and... running.
Also, the author of The How of Happiness places a high value on spirituality and religion. She is clear that one does not pursue spirituality, truth and meaning in order to become happy, but that happiness is without question, a byproduct of this pursuit.
ONE PODCAST I particularly enjoy is Faith and Philosophy by Clark Carlton. Professor Carlton, a convert to Orthodox Christianity, brings a sober understanding of the world and its cultures to each of his discussions. 
