That is as true for fiction or non-fiction. The writer has to really know their subject. It is really important to remember that the readers are a lot smarter than the writer. Also, good writing has to do with rewriting. You will never get it right the first time. So you rewrite and rewrite again until you get it right. Until you, and the reader, will be able to visualize what you're writing about.
Michael ScottI am a great believer that all the primary research has to be done before principle writing begins. I'm a huge advocate of plotting.
Michael ScottThe most reward experience is having another writer come up to you and say that they started writing because they read my books. That is how writing as a profession continues: readers becomes writers who inspire new readers.
Michael Scott