One of the conversations that came up during the Clarion Day Workshop was how critique groups sometimes become rule-based, and they start to develop lists of Things A Writer Shouldn't Do. A writer shouldn't use flashbacks because it slows the plot and confuses the reader. A writer shouldn't start a story with dialogue.
This is incomplete advice which leads to auto-pilot critique and writing. The complete advice is There Are Things A Writer Shouldn't Do Poorly. For example, poor flashback use will confuse a reader, but skillful use of it will make a story work.
The take-away reminder is that a skillful writer can break the rules.
Another gem of advice that I was reminded about was how good writing is like walking on a narrow plank. My personal plank is the details plank: fall off it one way, and the story is buried what I call Tolkien Sclerosis; fall off the other way and the reader can't see the scene on the page or gets confused because the writer has assumed knowledge on the reader's part. One other dichotomy was when to use internal exposition verses character dialog to bring a reader up to speed about the story's situation. Go too far one way, and the characters are having flashbacks in the middle of sword fights; go to far the other way and the characters are having "as you know, Bob" dialog.