Ultimately the product that any writer has to sell is not the subject being written about, but who he or she is.
William ZinsserGood writing has an aliveness that keeps the reader reading from one paragraph to the next, and it's not a question of gimmicks to "personalize" the author.
William ZinsserEvery 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 Zinsser