You've got to get obsessed and stay obsessed

I'm an editor for a large publishing house, so I literally spend all day reading stuff other people write, haha. And the clues are different for everybody; for some it's the way they use punctuation, for others it's how they frame sentences, stuff like that that comes through even when they're trying a trope or tone they haven't tried before. With you, it's your paragraph structure - a lot of the time, you separate each moment of dialogue with action, rather than involving the two. :D And now you'll probably be able to think of nothing else! *evil cackle*