Leo Babauta, the author of the book "The Power of Less" and the guy behind the popular blog Zen Habits, recently published a post about how to be happy anytime.
I'm always happy with what I'm doing, because I don't compare it to anything else, and instead pay close attention to the activity itself. I'm always happy with whoever I'm with, because I learn to see the perfection in every person. I'm always happy with where I am, because there's no place on Earth that's not a miracle.
Link - and for Neatorama readers living is Sweden, as I do, here's a Swedish version of that blog post: Konsten att känna sig nöjd när som helst.