My dad has had a message on his answering machine (yes, he still has a machine!) that ends with "Have a great day. It starts with your attitude."
Sometimes I get my head right by remembering my heroes and their words. Favorite quotes of mine include lines from the movie Jerry Maguire. Dickie Fox, Jerry's sales manager shows up six times in the movie, like a chorus in a greek play, and says things like, "Unless you love everyone, you can't sell anyone" and "Roll with the punches. Tomorrow's another day."
I also like:
A man without self-discipline is like a city broken into and left without walls. Proverbs
Leadership is translating vision into reality. Warren G. Bennis