It really doesn't take much:
"There are three infallible ways of pleasing an author... 1, to tell him you have read one of his books; 2, to tell him you have read all of his books; 3, to ask him to let you read the manuscript of his forthcoming book. No. 1 admits you to his respect; No. 2 admits you to his admiration; No. 3 carries you clear into his heart."
- Mark Twain