The first step in making money writing what you love is to get over yourself. I don’t mean to be rude. What I’m saying is that you can’t think your writing career is about you. It’s not. It’s about what you produce for others.
Once you realize that, then you can move on to the next step, and that is: Match what you love to the need. Let’s say you love technology. Well, then, target your writing toward technology. If you’re doing a book, do market research to discover what technological issue or question your target audience is facing. Can you answer or address this question? In other words, start with what you love or enjoy and then find a way to write something that is meaningful in this area and that fulfills a customer need. If you write a book that does not solve a problem or answer a question or need, then you’ve wasted your time.