As an individual, you do the writing, whether it is fiction, non-fiction, technical writing, journalism, etc. However, there is a transition to teamwork as you bring your idea to market via the editing and publishing process. To become a financially successful writer, you need to adapt to that evolution. You can write for yourself, or you can write professionally. Passion-driven people need to read and write true to their voice.
Good writers write as they speak.
You may need help refining and polishing what you are doing. You want to make the best first impression, and learn to sell faster . Different types of writing emphasize different viewpoints i.e. emotional versus intellectual versus mystery, etc. You should know what kinds of books are a good match with your writing interests, and approach the publishing houses that publish those types of books. Internet companies are the newest media that need writers, as well as the more familiar, newspapers, television stations, and radio, which is easier to get into.