No one is born a great writer, just like no one is born a great tennis player or a great musician. Even the supremely talented Mozart had to learn to play the piano. This is good news, for each of us can become a good writer, and even a great writer, if we're willing to put in the time. Here are some suggestions for moving towards greatness.
1. Write! I know, I know. How can that be the secret? It's so obvious. Writers write. Good writers write a lot. Great writers write even more. Write a daily journal entry. Write poems. Write stories. Write from prompts. Write down what you see, what you hear, what you taste, smell, feel. Writing is a skill and to get good at any skill, you have to practice. Write whether anybody reads your work or critiques it. Write every day and you'll get better.
2. Read! Read everything: newspapers, magazines, graphic novels, potboilers, essays, Internet postings. But focus as much of your reading as you can on the greats--the great essayists, the great poets, the great novelists. Human beings imitate language. That's how we learn to speak. We have an innate ability for language and we hear and absorb it and speak it. Similarly, we read great prose and in a mysterious process, we absorb the patterns of sentence structure and phrasing. If you read great stuff, your own writing will improve.
3. Read some things twice. Read a bad novel for the plot and then reread it and figure out why it isn't good. Why is the dialog corny? Why are the characters flat or unbelievable? Why is the plot thin? Similarly read great writing twice. Why is it beautiful? Why is it original? Why is it great? How does it work?
4. Keep at it. There's room in our world for many more beautiful books, stories, poems, essays, meditations. Few novelists publish their first novel. Often what is called "first" is first published. In a drawer or computer file sit two or three or eight other books that were all part of the learning process. No athlete would expect to win an award for his first Little League game; no painter would expect to sell his first-ever painting.
Writers write and read. Keep at it until you're as good as you can be and then keep going.