Heard it before? Most students get that message over and over again. But there's a lot of satisfaction in writing what you don't know. In fact, that's the basic idea behind many paying writing gigs. Newspaper reporters, for example, don't know everything about everything before they get started. They ask questions, get answers, and in the process, gather material they can use to write their articles.
When you open your mind to writing about subjects you're not familiar with, you can write about anything. There are no limits, and that's exciting. There is, however, one major hurdle to overcome. That would be your ignorance about the subject matter you plan to tackle. How, for example, can you write a story about a girl living on a horse farm if you've lived your whole life in the city or suburbs?
The answer is simple: research.
Once you know what you want to write about, no matter how little you know about it, you can find out more. There are many ways to approach your research. In the case of the horse farm story, you could actually visit a horse farm to get some details. You could also interview a horse owner, read about horses and their care, attend horse shows, watch youtube videos of equestrian events, and the list goes on wherever your imagination might take you.
It doesn't matter if you start writing the day you start researching or when you decide you're done. (Some writers get really caught up in research - it's fun to learn about something that interests you!) The point is, once you start, you'll know more about your subject than you did the day before. That knowledge allows you to write about it.
So in the end, maybe once you do some research, you're writing what you know after all!
Got your own ideas about how to research writing topics? Please share!