Lit agent Rachel Vater has some questions you can ask to help you understand what your strengths are as a writer. Here’s one:
What feeling do you want when you read a book? (This is a more important question than it would seem — Not as obvious of an answer as you might expect.)
Great question, eh?
The feeling I want when I read a book is transported. I want to be lifted out of the here & now and taken to vantage point where reality is framed in archetypal or even small-d divine terms. The redemption may be through love, or joy, or coming to terms with one’s self, doesn’t matter really, as long as I’m lifted. This applies to non-fiction as well incidentally; for instance, Peter Ackroyd’s histories transport me by shifting my perspective via point-in-time.
Vater has also summarized the main strengths of a number of writers, wonderful way to put ourselves in an agent’s place as she experience our writing.