First taboo: no matter how beautifully written, don't let description bring your narrative to a halt. The author of a novel must keep this in mind: don't over-describe anything, whether it's the Tetons, the sunset, or the zebras on Waikiki Beach. Otherwise, the strength of your narrative is going to suffer.

If you were given a chance to go back in time, what moment of your life would you choose to go back to? Why would you want to go back to that moment?"