What are the best ways to train yourself to become a great writer?

The obvious answers to becoming a great writer are reading and writing a lot. However, these two items are nuanced. Reading a lot, for certain, but not just passive reading - active reading, and a vary what you read. Writing a lot is putting the theory into practice but rewriting, revising, and editing to fine-tune and polish are equally important in becoming a great writer. Develop keen research and observation skills, and always be willing to experience new things. These are particularly important for relating to your audience and helping you write authentic and plausible narratives. Becoming a great writer also takes the "4 Ds": dedication, determination, desire, and discipline. If you have those, it's just a matter of time.

Working with various editors and comparing style guides from various sources has helped me hone my craft. Getting peer reviews is also helpful, especially when you require technical experts to ensure the accuracy of your writing.

Develop a desire in writing then, be ready to learn from others. Read more books since you it act as a source of suitable vocabularies and good writing styles.

Being creative and assertive in your writing. Using a journal to write anything that you have on your mind. What is inspiring to you doesn't mean that it sparks other's interests. I like history and I use some humor to write it. Because how do we really know that people didn't eat tacos in the 18th century. It's kind of hard to think of George Washington driving a car. I can see Abraham Lincoln driving one though. Have you ever thought of minimum wage as a salary? Instead of hourly wage?

I've found the most helpful practice is to listen to others. Listen to your sources, and don't be afraid to discover viewpoints that challenge your original assumptions. Often that's where the good material is. Maintaining relationships with people whose perspectives you trust and value is equally important.

Very quickly come to the realisation that other people don't know what's in your head. They don't understand the essence of you, your proclivities or your background. The way you see things is unique. You therefore have to prepared to explain and justify things that to you seem obvious. This is the essence of being a great writer. Once you crack this particular nut your writing becomes fuller, more feature-rich and more appealing to your readers.

Pick a project and finish it. It doesn't have to be for everyone's eyes (it's better if not), but practice finishing your work. Read widely (not just your genre, but as many as you can get your hands on). If you're looking to become a writer that sells their work, submit! Never submit for exposure if you can help it. If you believe in a magazine's mission and they aren't able to pay, tread carefully but support the magazine if you can. Find a writer's group and check in regularly. You don't have to write every day but try to write a lot.