Good grief…that’s a puzzler. I can only give my opinion. I believe the writer has to love language, words, the music of communication, the choreography of thought expressed. But love of these things is not enough. Unless the writer has a rare natural voice, he or she must read widely, write regularly, exercise daily the writing muscle in order to gain control of it. And most of the time the author must have something to say. It is usually not enough to spin beautiful or humorous phrases; there must be substance to the words. And there must be a willingness on the writer’s part to sacrifice, not only words, sentences, passages, entire chapters if they do not advance the plot or contribute in some measurable way to character development, but authors must also be willing to sacrifice time, relationships, pleasures. Finally, the author must experience life with all of the senses and re-purpose that experience into the subtle movement of the tale to be told. Even then, this recipe may not yield a good author, but it certainly improves the odds.
For additional info: http://www.childlitassn.org/phoenix-award