Find your own voice. That's what teachers told me in creative-writing classes when I was in college 20 years ago—it's what the Guardian trumpeted as the goal of creative writing courses just this month. It's what old grizzled writers always tell the young, bright-eyed, bushy-tailed up-and-coming wannabes. With one voice they all declare, "You are unique, you and your bushy tail. Get that uniqueness on the page. Every one of you speak your true self truly, as only you can speak it, in a swelling chorus of soulful idiosyncrasy."
I took the advice to heart, or tried to, when I was young and bushy-tailed and trying (like all the other writers) to get my work published in literary magazines read only by the other writers trying to get their work published, so we could all bond in appreciating one another's individuality. I discovered that when my own voice was like Flannery O'Connor's, I could sometimes get accepted; less so when my voice was like Ogden Nash's, as in the clerihew below that I wrote years ago when I was young and foolish and trying to get into MFA programs:
Beneath the wig of Mr. Johann Sebastian Bach,
Vermin flock.
The chittering of invertebrata
Inspired a fugue and toccata.
You could argue with Harold Bloom about whether or how great writers past found their own voice (via agonized Bloomian rejection of mentors or via other means.) But the argument is academic; for most folks, if you're going to be successful, it's best to find that your own voice is similar to the voice of someone on the prescribed list of folks who found a good voice before you. (Pro tip: Ogden Nash and Edmund Bentley are not among them.)