Keep track of the nice things people say about you, and of the people who are exceptionally happy with your work. When you are having a hard time at the office (or want to use some testimonials in your marketing materials) you have a list handy for a quick pick-me-up.
And in case you think it is a bit conceited to keep track of the people who love you, remember that you will build a far more successful business by marketing to your happiest customers than your unhappy ones.
Thanks to my friend, Steve Nipper, for the tip.