I prefer a different maxim: Know what you write.
Let's say, for example, you're writing about hard science that is based in reality. Internet, nano probes, genetic engineering, prosthesis, bionics, etc. Every one of them are favorites of writers because they evoke the sense of wonder in the reader. They are rife with potential because no one really knows how far the technology can go, and your guess is just as good as the next person's as to what the next stage of technological evolution will be.
|I, for one, welcome our robot overlords...|
|Says the voice of God...|
Here's where things get weird: You owe your readers. Seriously, you do. You owe them the best possible reading experience that you can muster. Why? They're buying your work. If you betray that trust, well, they won't be buying your work anymore, will they?
So, instead of relying on your own limited experience to write something and hoping it's in any way accurate, how about doing a little research? If you're reading this, you have access to the sum total of all human knowledge. It's called "Google." You can seriously ask anything about anything and the answers will appear. Then you can read about it and appear to know what you're doing. But it doesn't stop there. You can actually contact real, live people who know about stuff. For some of these people, the things you write about are, in fact, their jobs. Like, policemen, fire-fighters, doctors, lawyers... And people really like to talk about themselves and what they do. So call them up and ask them questions. It can't do anything but help.
But wait, there's more.
|Tell 'em all about it, Billy!|
How about this... You want to write a scene of your POV character getting kidnapped and thrown into the trunk of a car. What do you do? First off, you call your best buddy, someone you trust, who you hope doesn't have a sick sense of humor. Then you climb into the trunk of his car and have him drive around the parking lot. You think I'm kidding, but I've done this. And now I know what it feels like to be jostled around in the trunk of a car.
|Seriously, I've done this.|
Until next time...