I sometimes speak at writers' conferences--something I really enjoy doing--and one of the topics I often cover is time management for writers. My first book was about time management, and I've always felt it was an important topic because ultimately time management is really life management. It's not about color-coding your files; it's about deciding what's important, making a commitment to it, and dumping the low-value tasks that don't move you toward your goal.
For would-be writers, I think the first rule is to identify yourself as a writer. When you meet someone new and he or she asks you what you do, answer boldly, "I'm a writer." If you say, "I'm an office manager (or a salesperson or whatever), but I dabble in writing a little," you'll always put the other identity first. Something will always come up to get in the way of your writing. Get your writing identity up front. "I'm a writer who masquerades as an office manager." If writing is your dream, claim it and create the reality.
And don't be abashed by the next question, which is "Published?" If you haven't been, your answer should be, "Not yet."
And then go out and learn as much as you can, read as much as you can, and write as much as you can. You'll never see a byline or your name on a book if you don't try, and you won't try if you don't think of yourself as a writer first.