Another writing principle from my friend and mentor, Harold V. Cordry:
Never “talk down” to your readers. When you write, it’s between yourself and a reader (singular). [Maybe this is only a personal philosophy that has evolved over a lifetime of writing but to me it seems a good one.] This lone reader is someone you like and care about and whose intelligence and character you respect.
If you sometimes devote a little extra space to explaining a point, it’s only because it’s so important to you that this reader understand precisely what you mean (or perhaps it’s for the “other” readers that you are taking pains to explain something more thoroughly). [I wrote “more fully” and twitched because full is full and fully is logically fully and therefore cannot be modified by “more.”]
One’s best writing comes, I believe, when one is speaking consciously to this single reader, who is both intelligent and sympathetic.