A: As I have said repeatedly, I have no simple, easy answer that will make everyone happy. Some people with serious problems need to see a therapist and get professional help. And many of us have such deep-grained habits that it won't be easy to change overnight. Plus, we all have our temperaments that will put some limits on how easy it for us to be happy. So there is no magic elixir. Having said this, I think there are some steps people can take to insure that they are as happy as they can be (although nothing will make us happy every moment, fortunately). First, we need good friends and family, and we may need to sacrifice to some extent to insure that we have intimate, loving relationships - people who care about us, and about whom we care deeply. Second, we need to involve ourselves in activities - work, for example - that we enjoy and value. We are likely to be best at things we value and think are interesting. Finally, we need to control how we look at the world. We need to train ourselves not to make a big deal of trivial little hassles, to learn to focus on the process of working toward our goals (not waiting to be happy until we achieve them), and to think about our blessings (making a habit of noticing the good things in our lives).
Another good Q from the same site http://internal.psychology.illinois.edu/~ediener/faq.html#SWB