Write Every Day
This should go without saying, but here goes. To become a better writer, you must write every day. Writing is like every other skill that can be improved through repetition and practice. Or a muscle that must be exercised to grow big and strong.
It’s the old “How do you get to Carnegie Hall” routine. Practice, practice, practice.
Or the “10,000-hour rule”, which states that to master any skill, you must practice for 10,000 hours or more. If you want to become a better writer, write more words more often. End of story.