Joseph Epstein in The New Criterion:
After thirty years of teaching a university course in something called advanced prose style, my accumulated wisdom on the subject, inspissated into a single thought, is that writing cannot be taught, though it can be learned—and that, friends, is the sound of one hand clapping. A. J. Liebling offers a complementary view, more concise and stripped of paradox, which runs: “The only way to write is well, and how you do it is your own damn business.”
Learning to write sound, interesting, sometimes elegant prose is the work of a lifetime. The only way I know to do it is to read a vast deal of the best writing available, prose and poetry, with keen attention, and find a way to make use of this reading in one’s own writing. The first step is to become a slow reader. No good writer is a fast reader, at least not of work with the standing of literature. Writers perforce read differently from everyone else. Most people ask three questions of what they read: (1) What is being said? (2) Does it interest me? (3) Is it well constructed? Writers also ask these questions, but two others along with them: (4) How did the author achieve the effects he has? And (5) What can I steal, properly camouflaged of course, from the best of what I am reading for my own writing? This can slow things down a good bit.
More here.