How do we know when we’re writing with own authentic voice? It’s not that you sound like absolutely no one else. Given the limited number of words in our vocabulary, it’s unlikely for an author not to resemble another author sometimes. Even William Shakespeare could sound a little like Christopher Marlow.
It’s not that you’re perfectly consistent. A consistent author would sound like a robot. Even Hemingway added a qualifier now and then.
It doesn’t need to be perfectly grammatical or the Queen’s English. It has nothing to do with correctness or decorum.
It isn’t filler and it isn’t just the first thing that came to mind. An authentic sentence is written with intention.
It isn’t there because legal said so, to cover someone’s ass or to offer plausible deniability. An authentic sentence wants to be read.
The writer doesn’t dumb it down, nor does he adorn his ideas in rich, frothy vocabulary. An authentic sentence is as skillful and capable and smart as its author, no more, no less.