The key is to find a cause to help in which you truly recognize the blessings/fortune/privilege/opportunities you have.

I've volunteered with animal shelters, geriatric hospitals, youth sports, and with veterans. Animal shelters were fun because I love animals, but they didn't humble me like working with veterans and the elderly. Every time I work with those groups, I learn more about life, and get insight into ways I could change how I'm living to be a better influence on society. I think that's the key - at least, that was the key for me.