I increase my curiosity about a topic by attending closely to what specific questions related to that topic I'm not confident I know the answer to, what predictions I would make differently given higher confidence in various different answers to those questions, and what the consequences might be of being right about those predictions.

Also, the longer I spend trying to think of such questions/predictions and failing, the more confident I become that increasing my curiosity about the topic is not a productive use of my time.