How Can I Write What I Know When I Know So Little?

We’ve all heard write what you know. I say know what you write. If we had to stick to
write what you know, there would be many books by our favorite authors. 
In fact, I’m
changing that up to: Include what you know and
learn what you don’t. That’s more fun, don’t you
Do you have to journey to a far-off land to do your research? Road trip! It’s more fun, but if you’re a new writer, who hasn’t got deep pockets, then plan your road trip via the Internet. 
Do you want your protagonist to be a law enforcement officer? Go to your local police. They often offer a citizen’s police academy to acquaint the citizens with police activity.
Want your hero to be an archeologist? Go dig up your back yard, see what you can find. Okay, that’s not enough, you’ve got to do more research. But you get the idea.
Most writers could have a coffee barista as a protagonist, since most of us have spend countless hours in coffee shops. See? That’s a “know”.
The main character in my debut novel, Chapel Springs Revival, is a potter. I’m not a potter. Neither is
the hubs, although he is an artist. But I researched making pottery, went to
visit a potter in his workshop/gallery. I observed, and used what I learned. I
used my “know” in the Southern setting and the food.
In another book, not yet
published, I placed it in both the South and Albany, New York in the capitol.
My main character was a pro-family lobbyist, something I know well, since I’d
been one. I was always fascinated with the underground between New York’s
capitol and the legislature and other buildings in the downtown area. I used
In my sophomore novel, Chapel Springs Survival, I have Claire trying out a new art form. And I had to learn
about how it was done. Boy, am I glad I did. I thought it was done a certain
way but found out it wasn’t. (Am I teasing you? Yes!)
The moral of this is don’t be hampered by thinking you can’t write about something you
don’t know. Learn about it. Research
it well, then write!