A soup of subcategories - how (not) to make sure your novel fits neatly within genres

Today, because I'm getting back to work on my current project, I'm wondering how I choose to write what I write.

Specifically, I wonder how I chose the topic for my first novel, The Day The Earth Caught Cold. I started it a long time ago (longer than I care to remember) so it's tough to do more than guess at this stage, but it's about severe and sudden climate change of the ice age variety, so I think I must have rewatched The Day After Tomorrow not long before I started writing.

I like apocalyptic settings because they open up everything for grabs - settings look different, the rules of society are gone, people have more freedom to do unpredictable things. Best of all - and it's a blessing I appreciated more and more as I wrote - there's no technology to deal with. I really do believe sometimes that technology has killed fiction. Most of the Biggles books I grew up on would have been ruined by mobile phones, for a start - the plot always revolved around Biggles and his team wondering where each other were when they didn't turn up at the rendezvous point and having to go and look for them. Mobile phones would have just ruined that.

I digress. An apocalyptic setting gave me a lot of freedom with The Day - and it turned out I just loved writing about snow and ice. In fact, I miss it now. On the other hand, apocalyptic stories are necessarily rather gloomy in outlook and my writing style is quite upbeat, in fact I'd probably fit myself in the cosy category. A cosy apocalyptic thriller? I can't see them creating a new section for that in bookshops any time soon.

Anyway, for what it's worth, The Day The Earth Caught Cold is a cosy apocalyptic thriller with a dash of science fiction and suspense. I am determined to have no such uncertainty over my new novel, The Crooked Man. It's definitely a cosy thriller with some detective story elements. There doesn't seem to be a shelf for that in the book-shop either...