One of the most often repeated pieces of writing advice out there is to write what you know. But what exactly that means is something of a point of debate. Does this mean you should only write things you have firsthand experience with? Or can you write anything that strikes your fancy so long as you do a bit of research? Personally, I lean more towards the latter than the former.
I think to write something that feels real and allows your reader to immerse themselves in your story, you should have a strong understanding of what you are writing about. That said, you aren't writing nonfiction and your writing can take some liberties. So, how can you find a middle ground?
- Consider what you already love -
For most of us, there are certain topics that we are passionate about. If there is a topic you find yourself reading books and articles about or listening to podcasts on, consider how you might work that topic into your own writing. Your background knowledge of the topic already puts you ahead of the curve when it comes to research, but more importantly it should be something that you are passionate about. Writing a book is hard work, but if you can tie that work into something else that you are deeply passionate about, it can help you to keep going and to stay engaged. Personally, I really love folklore, true crime, and psychogroegraphy. These are subjects I love and have been learning about for years. By incorporating bits of these topics into my writing, it is a way to bring a little extra passion and spark into my stories.
- Read widely in your genre/topic -
I've mentioned it before in other posts, but you should read as widely as you can, especially within your own genre. While you can certainly write a murder mystery without having read one, that means that you are coming into the story with no knowledge of the genre conventions or what tropes have become tiresome and trite. In order to break the rules effectively, you first need to know what the rules are.
- Do your research -
I've written a blog post on research before, but I can't stress enough how important research is. If you are writing about a subject you are already passionate about, you likely already have the base level of knowledge about the subject. Instead, you can use your research time to delve deeper. While your novel doesn't need to be perfect, avoiding any glaring errors helps to make the entire world of your story more immersive and believable because readers aren't pulled out of the story by a noticeable mistake.
Ultimately, the bottom line is that writing what you know has to do with writing what you care about. It doesn't matter if you don't know absolutely everything there is to know about a subject. You don't have to change your career mid-life to become a cop because you want to write detective novels. Instead, the goal is just to be able to create writing that feels true. So, enjoy life, have great experiences, read a lot of books, and cultivate your passions. Your writing will be better for it.