Advice from Editorial Anonymous, in response to a reader question:
There are different definitions of what makes a writer “great”, and the ways
that different writers go about being their version of great varies a great
deal, too. So unfortunately there is no simple formula for greatness. But I do
strongly recommend reading every day and writing every day, faithfully and
persistently, and wanting to live the rest of your life that way. Greatness is
not achieved through a passing interest or periodic dabbling, and most writers’
first work (or works) do not get published. I can tell you at least that no one
ever achieves greatness by wanting to be a writer– only by being one.
Fabulous advice, which essentially boils down to: Read. Write. Read some more. Write some more. Rinse. Repeat.
You don’t need to have an MFA in order to imagine a fabulous story or to craft grammatically appropriate (or even interesting) sentences. But you do, IMO, need to be able to identify the key components of story telling (i.e., pacing, plot, character development), a skill developed by reading. (Not to mention the fact that reading, also IMO, makes you a more interesting storyteller. You learn about things, about the world at large, about details that punch up your storytelling.)
And even if you’ve never taken a creative writing class (I haven’t), IMO skill at writing can be developed over time. I wrote in academic and professional contexts for many years. Fortunately, I was also edited, so I could learn to write by the doing of it. If you aren’t academically trained and don’t write at work, a critique group might help you develop your skills as a crafter of sentences. Practice is essential, and guided practice (i.e., someone pointing out errors so that you can learn to correct them) was a crucial component in my own training as a writer. Self-editing (i.e., identifying your errors so that you can correct them) falls into the same category.
Other suggestions, commenters?
Speaking what I've written aloud is one of my favorite techniques for finding poor quality prose in what I'm writing. I read that in one of my editing/writing books. It almost always sounds good when I read it or write it, but if I speak it aloud its easy to spot passages that don't quite flow.
Ok posting another comment to your post. I've been thinking a lot about it lately; more and more I'm convinced that what makes a great writer is simply wanting to write. In my opinion there isn't any other formula or magic to it, you just have to want to do it. Have a story that you want or need to get out and do so, write it.
One of the concepts (I almost said things, but my word processor is now trained to freak out when I type 'things') I've learned is that by just writing you learn more. Keep doing it and you will learn, then read what you've written and you'll find your way.
In some ways writing is like music, there are basic formulas, I V, IV is a chord progression, as start middle and end are a story. But also like music if it comes from you there aren't many wrong answers.