If your book is fiction, how could you change it to make it a nonfiction book? If your book is nonfiction, what could you do to turn it into a story? Hollywood has done it (What to expect When You’re Expecting; He’s Just Not That Into You), so how could you do the same thing?
Obviously, I'd have a pretty tough time with that. I write about faeries and living dreams and talking rats and self-aware zombies who want equal rights. If you need help with any of those things, you probably need a good psychiatrist, not a book.
I've been re-watching Buffy: The Vampire Slayer from the beginning. It's been a really, really long time since I've seen all of these seasons, and some of the earlier seasons I never saw all the way through so it's been a real treat for me. Anyway, one of the many things that I've always respected about the writing in Buffy is its economy of theme. I suspect this is part of the reason I never liked Angel as much as a series, despite similarly witty writing and good characters. Angel didn't have quite the same hyper-focus on theme that Buffy does.
Here's what I mean: In the Buffyverse, problems get personified as demons. There's all sorts of theme episodes where, sure, we're technically talking about monsters -- but we're actually talking about growing up. Lots of shows do this (Smallville is another program I enjoy that's quite similar in that regard, at least for the first few seasons) but Buffy managed to keep entire seasons on theme. Without being pedantic or beating you over the head about it -- just quietly weaving a couple of themes together as the storyline progresses.
Anyway. Why am I talking about Buffy? Because it gets back to the beautiful thing, to me, about fantasy. The reason why fantasy (and sci-fi and horror) is so compelling is because it holds up a fun-house mirror to our lives and forces us to look at things that we might not otherwise see. By changing up some of the rules of real life, fantasy draws attention to things that matter. Metaphors have this really magical ability to clarify things, and fantasy is the best for that (in my opinion, at least).