Once you have that problem or need nailed, the next step is to validate that idea and make sure you’ve actually got customers who will pay for it. This means building a minimum viable product, getting objective feedback from real customers, incorporating updates, testing the market for demand, and getting pricing feedback to ensure there’s enough of a margin between your costs and what consumers are willing to pay.
What will also help your earning potential is to specialize in one style of writing, and maybe even one particular subject. You see, writing on the same subject for hundreds of hours each year makes you an expert on it. To paraphrase Cal Newport, “…you’ll build up a lot of career capital through deliberate practice.” It’s how you become so good that clients can’t ignore you.

Be professional. When you submit a résumé, don’t type it in ALL CAPS and please don’t avoid the caps lock like the plague. Know how to use it without looking incompetent. Write in complete sentences with proper grammar. Of course, there will be exceptions, but even with the exceptions, you must keep it professional. You’re building their view of you.