- Exercise regularly. Aerobic exercise(whatever that means for you) that you can maintain without develop injury or over-training will be your baseline. Endorphin is what you are after, since it provides a boost of immune system, better sleep, less anxiety and increased overall health.
- Be outside in the sun everyday, take a walk or sit and read a book.
- Cut out any consumption of large amount of drugs: alcohol, sugar, nicotine...
- Talk to someone about your worries and sprinkle some Zen in your life.
- Help someone else for no personal gain, but don't let it consume all your time.
- Understand that all things are transient, nothing is static, and trying to be eternally happy is impossible and the quest for such a thing will make you unhappy.