Get people to critique your writing. Ultimately, writing is communication and recipients can give you a lot of actionable feedback. Without such a feedback loop it will be very hard to become meaningfully better at writing. Often the feedback will be relevant to a particular piece, though sometimes to writing in general.
You can also find someone else who wants to become a better writer and offer advice to each other. Reading another person’s writing while thinking about how it might be improved, and discussing your suggestions with the author, might benefit you as much as the advice you receive about your own writing.
