I didn’t think about genres when I started writing. I never said, “I want to write a Contemporary Realism story.” Instead, I pictured an IT worker in a small engineering firm dealing with a hack. Same with Crystal Grove; I began with the idea of Reiki and crystals in the backyard. To date, I’ve written amongst three genres, Contemporary Realism, Magical Realism and Post-Apocalyptic (and a sub-genre, post-industrial).
Should a developing author follow their ideas and inspiration or focus on one genre? Both King and Grisham are best known for one genre (horror and legal thriller, respectively) but successfully write other styles as well (fantasy, realism, Christmas tales, etc.). The vast majority of authors stay with one genre, sometimes employing a nom de plume if they veer outside of their self-defined lines.
Sticking to one genre has advantages. It allows the author to become an expert. Read the best writing in the genre, know the tropes and expectations of the reader. When I posted a few chapters of Crystal Grove on Scribophile, one reader commented that my description made the piece sound like a haunted house story and she chided me for not meeting her expectations. Understood. This focus provides a chance to write better in that genre and build an audience. If an author has fans, most likely they read only in that genre and may not follow you as you hop between types.
I worry, though, that writing in one genre is too limiting, especially early (career-wise). I follow inspiration wherever it lands. If I had a powerful vision of a fantasy world of swords and goblins, I’d like to pursue the idea, likewise with a romance or office mystery. Counterpoint is I could always shoe-horn these other ideas into a genre. And it’s restrictive to limit the world of the possible to one set of ideas and tropes (although guide rails are very important).
I’ll continue to dabble in the different genres for now. If any of my stories ever caught on, I’d change my approach. One of my goals as a writer is to have one-hundred non family and friends read my work. I’d focus on a genre if I ever crossed that barrier and gained a fan base.