His advice, as appears on NPR's Web site, are:
Give yourself permission to be human. When we accept emotions -- such as fear, sadness, or anxiety -- as natural, we are more likely to overcome them. Rejecting our emotions, positive or negative, leads to frustration and unhappiness.
Happiness lies at the intersection between pleasure and meaning. Whether at work or at home, the goal is to engage in activities that are both personally significant and enjoyable. When this is not feasible, make sure you have happiness boosters, moments throughout the week that provide you with both pleasure and meaning.
Keep in mind that happiness is mostly dependent on our state of mind, not on our status or the state of our bank account. Barring extreme circumstances, our level of well being is determined by what we choose to focus on (the full or the empty part of the glass) and by our interpretation of external events. For example, do we view failure as catastrophic, or do we see it as a learning opportunity?
Simplify! We are, generally, too busy, trying to squeeze in more and more activities into less and less time. Quantity influences quality, and we compromise on our happiness by trying to do too much.
Remember the mind-body connection. What we do -- or don't do -- with our bodies influences our mind. Regular exercise, adequate sleep, and healthy eating habits lead to both physical and mental health.
Express gratitude, whenever possible. We too often take our lives for granted. Learn to appreciate and savor the wonderful things in life, from people to food, from nature to a smile.
A related article called The Science of Happiness by Craig Lambert is published on Harvard Magazine (January-February 2007), where he discusses how psychology explores humans at their best.