In the middle of this excellent New Yorker article debating the benefits of a university education, this paragraph offers good advice for the art of good writing:

When he is not taking on trends in modern thought, Professor X is shrewd about the reasons it’s hard to teach underprepared students how to write. “I have come to think,” he says, “that the two most crucial ingredients in the mysterious mix that makes a good writer may be (1) having read enough throughout a lifetime to have internalized the rhythms of the written word, and (2) refining the ability to mimic those rhythms.” This makes sense. If you read a lot of sentences, then you start to think in sentences, and if you think in sentences, then you can write sentences, because you know what a sentence sounds like. Someone who has reached the age of eighteen or twenty and has never been a reader is not going to become a writer in fifteen weeks.

If you want to write well, you should read good writing.