There are lots of things you do without understanding how you do them. Mostly this is not a problem. But if you are hired to teach others to do whatever it is, you run into a problem. When it comes to teaching writing, it can be a major problem. Art Scheck eloquently expresses the hollow feeling that can result in an article in The Chronicle of Higher Education.
It's something I've certainly dealt with. Personally, my approach has been to look to psychology, psycholinguistics and cognitive science for answers. Perhaps hints or notions is more like it, but it's better than having no clue at all.