This question is lifted from author Sahar Sabati's informative Ask an Author series, which ran from 2015-2016 and included responses and reflections from English-speaking authors from around the globe. Since I'm often asked these questions by readers, I have republished my answers here with Sahar's kind permission.
I’d always written bit and pieces, stories and letters and things, and over the years several friends and mentors had suggested I write a book, but it wasn’t until eight years ago that I decided to give it a proper go. My first book—the first one I wrote, not the first one published—was a chick-lit entitled A Dash of Reality. It’s the story of Mel, a ditzy marketing assistant who dreams of becoming famous. But Mel’s sleazy bosses have other ideas and she risks losing not only her job, but also the apartment she’s worked so hard for. Happily, Mel comes up with an idea which might save both. She comes up with an idea… an idea… what idea? I’d pantsed my way through the first few chapters and now I had to come up with an idea that would carry the plot for the rest of the book. Something fun. But what? What could ditzy Mel do that might save her? There’s an old adage in writing that you should ‘write what you know’ so being a newbie I did just that. By that time, I’d run nearly 20 marathons, ploddy slow ones, but I knew something about finishing a long distance race. I drew on those experiences—yes, that bee incident actually happened, and yes, that’s exactly how sports bras work—I borrowed anecdotes and characteristics from running friends, I even used some of my favourite running routes, to carry Mel’s story.