Write a list of ten things you know how to do well, things that even if someone scoffed or doubted you, you’d be like, “yeah, no, you’re wrong; I’m so good at this/know a lot about this” without even a moment of hesitation. These things can be anything, and don’t necessarily have to be connected to your professional work at all, or they can be a mix of the two. (For example, I’m very confident in my ability to editor other people’s writing, but I can also parallel park better than anyone I know. Simply no argument. The end. Go home. Bye. I’ll be putting both on this list.)
Next, write “the beginner’s guide to…” about one of those things that you know about, but be sure to include why you’re the person the reader should listen to. (A personal experience? Formal training? Years of practice?) It can be anything: making sushi, accounting, getting health insurance, being successful on a board, running for office, making a baby sleep, getting a vaccine… whatever. Just write, and know that you know.