Contemporary research shows that happy people are more altruistic, more productive, more helpful, more likable, more creative, more resilient, more interested in others, friendlier, and healthier. Happy people make better friends, colleagues, and citizens.

One reason that challenge brings happiness is that it allows you to expand your self - definition. You become larger. Suddenly you can do yoga or make homemade beer or speak a decent amount of Spanish. Research shows that the more elements make up your identity, the less threatening it is when any one element is threatened.

Work harder to appreciate your ordinary day.

In general, religious people seem to be happier than non-religious people - under various definitions of "religiosity," such as church attendance or professed spiritual beliefs.

Your unhappiness doesn't help anyone else - and in fact, as I mentioned in another answer, happy people are more altruistically inclined. So happiness is not a selfish goal.

Don’t let the perfect be the enemy of the good. Lower the bar. Actually spending ten minutes clearing off one shelf is better than fantasizing about spending a weekend cleaning out the basement.

People feel happier when they feel like they're progressing. When they feel like something in their life is growing or getting better.