The core philosophy that I go back to for basically every part of writing is "know what you're doing, and do it on purpose."
This goes from everything from word choice and sentence structure (understand the meaning and connotation of words you're using, be intentional with your word choice, understand grammmar rules and how you may be bending or breaking them) to plot, worldbuilding, and story meaning (know what genre tropes you are invoking or subverting, think through how one part of your worldbuilding relates to another and shape it accordingly, consider the implicit or explicit messages your story may be sending and make sure those messages are the ones you want to be sending).
I've talked about this before with writing advice as a whole, but I'll say it again here: use writing advice that applies to your story, and be intentional with it. Don't follow advice about building reader connections with a character when you are intentionally trying to building distance; don't follow advice about creating epic secondary worlds when that isn't your goal with the story.
Know what you're doing, and do it on purpose.
