From author Randy Henderson on the Science Fiction and Fantasy Writers of America blog:
The way to become a published writer is to write (and to submit what you write). Seems obvious, yet so many would-be writers produce that one story or novel and then rework it endlessly, or submit a story or three, get rejected once (or a hundred times), and decide to give up.
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I would add for writers specifically that the writers who are published are the ones who continued to write NEW stories, and submit those stories, and move past the rejections, until they were published.
Of course, today we have a wonderful short cut — self-publication!
I have repeatedly been asked for advice from writers who have written one story, or been rejected a few times, wanting to know how to proceed, how to become published. And sometimes as part of my response I make the mistake of mentioning self-publication as a possible future option.
. . . .
But too often, the would be writer latches onto that option as the answer, because the rest of my advice — to write and submit and be rejected until you are good enough to actually be published — requires work, and a lot of rejection, and letting many of your stories die an anonymous and unnoticed death.
And often the amateur writer believes their writing to be perfectly wonderful and worthy of being read. Unfortunately, it is hard to be objective about one’s own work.
Link to the rest at Science Fiction and Fantasy Writers of America blog