A writing career takes a lot of effort to build, but some efforts don't actually move you toward that goal. All anti-definitions are taken from my own experience.
- If you want to go with traditional publishing, you'll eventually need an agent and an editor. Do NOT call / email / pitch / camp out on doorsteps of agents or editors until your book is completely written and polished. If you're a brilliant writer, that's wonderful. Prove it by writing a book, not a letter. Not every brilliant writer is also a brilliant storyteller. Believe it or not, those are different skills. (I apologize to the editor I emailed when my first never-to-be-finished book was still in the idea stages, harboring a dim hope that someone would pay me to write it.)
- Most writers need a writing group for motivation and feedback. A writing group is NOT comprised of one thinking-about-getting-serious writer and her friend who thinks it would be fun... but doesn't care enough to prioritize writing over... anything else. Those folks can make good beta readers and idea-bouncer-offers, but they'll do little to motivate you to write.
- When writing fantasy, world-building is essential. World-building is NOT day-dreaming about your book in odd moments when you're in the middle of a mindless activity. Or, at least, that's not all it is. If you don't write it down, it didn't happen.
- Eventually, you're going to actually sit down and write the book. Maybe you write with an outline, maybe you're a pantser. Whichever is your favorite, you're NOT a writer if you don't sit down and write. Writers write. Serious writers write seriously. Dedicated writers dedicate regular writing time. If you find yourself in the middle of "writing" a book, but you haven't written anything in a few weeks... maybe you're not really a writer. There's nothing wrong with being a dabbler, but dabblers are unlikely to turn their hobby into a career. (Ouch.) To change your definition, change how you spend your time.
- Every once in a while, a writer comes along who is able to redefine a genre, brilliantly break hard-and-fast rules, and lead the charge into the strange and unknown. That writer is usually NOT a debut author. There are certainly exceptions to this, but keep in mind that no matter how brilliant your firstborn novel is, if it doesn't fit neatly within an established genre, follow every rule, and tread familiar paths, it is likely to be rejected. That's not fair, and that's not right, but that's the way of the industry. Find the rules. Follow the rules. Break them after you've proven yourself.
Have you ever tried something to build your career that didn't work?