People have different set points (or baselines) for happiness and that contributes to half of your happiness and another 10% can be attributed to positive life circumstances, however, there is still 40% of our happiness "capacity" that we have control over and are able to change. She argues that people can become happier and sustain higher levels of happiness by employing different strategies that are based on research. Although she has several strategies, it is not a one size fits all type of thing. Different strategies fit better with different people.
There are a couple of diagnostic quizzes on her website that you can take to discover how happy you are and strategies to use to become happier. According to her diagnostic quiz, my happiness set-point is average and the strategies that are the best fit for me are the following:
Your results indicate that you are more likely to succeed in becoming happier if you practiced:
Expressing gratitude: Counting your blessings for what you have (either to a close other or privately, through contemplation or a journal) or conveying your gratitude and appreciation to one or more individuals whom you've never properly thanked.
Committing to your goals: Picking one, two, or three significant goals that are meaningful to you and devoting time and effort to pursuing them.
In general, I do believe that I am a happy person, life is good and I am fortunate to have what I have. But if I have the potential and capacity to be happier, then these are strategies that are worth trying. It seems that becoming happier takes effort and it comes down to whether or not we are willing to make the effort to become happier. I think I find some comfort in knowing that it is in our power to be happy!