Every successful piece of nonfiction should leave the reader with one provocative thought that he or she didn't have before. Not two thoughts, or five - just one. So decide what single point you want to leave in the reader's mind.
William ZinsserDonโt try to visualize the great mass audience. There is no such audienceโevery reader is a different person.
William ZinsserIf writing seems hard, it's because it is hard. It's one of the hardest things people do.
William ZinsserI almost always urge people to write in the first person. ... Writing is an act of ego and you might as well admit it.
William Zinsser