Get the best people
It seems like an obvious bit of advice, but it gets overlooked when it comes to writers.
We fall for the lone creator myth, the picture of the solitary author working alone in their room with their singular voice.
That's bullshit. The best writers have a team of people—editors, first readers, publishers, cover artists, and publicists—making the author look good
Of course, I'm biased about this. I've written with a co-writer for many years. She brings a voice and tone that I don't have. She writes many words, and I always discover character moments and lines of dialogue that I'd never imagined. Working with her makes me a better writer.
Same with our editor and publisher. She fights to make our words the best version they can be so that our readers get the most engaging story. Then she shapes it into the best-looking book, caring about details I don't even consider, like how the words fall on the page and how it feels in a reader's hands. She makes us look good and ensures our books offer the most satisfactory experience.
Every step of the way, seek out the best people to elevate you and bring out the best work. It'll make you look better and improve as a creator as you are taught the lessons you would've never learned otherwise.