Happiness is definitely one state of mind worth having every now and then. But regardless of how easy it seems putting yourself in such mood, it sometimes becomes a difficult state for a lot of people putting into consideration the different factors evolving around our daily life routine and that also involves other people too. Drawing from all said above, I don't think there's any set rule that can be exercised in order to make one happy always. You just have to do whatever pleases and makes you happy which also involves shunning any external factor that might cause you mood swings. If one can achieve doing this, t I bet you can make yourself happy every now and then.