I don’t make a living as a writer but writing has made my living. Here’s my advice to improve as a writer in general, not as a writer of a specific genre or purpose, and not to improve a specific piece of writing.
0. All advice needs salt.
1. Recognize that all writing is personal and all reading is subjective. No one has a perfect lens. Be willing to be wrong. Even if you’re right, guaranteed someone else thinks you’re wrong.
2. Are you writing to be authentic or writing to be popular? Writing to persuade or to inspire? To amuse or confront? All of those may be in conflict at times. Recognize and accept the conflict, then make your choices in peace. See rule #1.
3. Everyone loves simple language.
4. But try not to be bland. This is the value of rhythm, voice, word choice, tropes and schemes, idioms, patterns, and so on.
5. There really is something to copying other people’s writing as a way of finding your own writing voice. So you need to read widely to find people worth copying. In general, avoid the angry advice writers.
6. Practice. Click the Publish button once in a while. You don’t end up pitching for the Yankees by reading about baseball.
7. Writing is pretty fantastic, isn’t it?
8. Language evolves. Just like foxes and toaster ovens. Accept it. Thank people for their critique of your apparent misuse of language and then please continue challenging the rules.
9.
10. Leave something to the imagination. Think of it like an offering to the gods.
11. No one cares about your writing as much as you do. See rule #1.