Bring to mind your favorite book. Take a minute. I know there are many favorites, but think about the one that made you FEEL the most. The one you can remember where you were when you read it, how the character's plight made you feel, and how much you hated for the story to end. The one that when you finished it, you closed the book with a sigh and thought about the characters for a week. It's on your keeper shelf, so go get it.
Without opening it, make a few notes and come up with your overall impression of the book. What are the impressions you recall? Heat? Cold? Sexual tension? Yearning? Longing? Loneliness? Familial warmth? Secrets? Desire for something?
An overall TONE is something you can't always find adequate words to explain. But if, when you think about the book, you remember the FEELING you got from reading it, it was a tone that made an impression. And it was in your mind when I asked you to select a favorite book.
As a writer, it's my job to put those feelings into each book. If I haven't written a story that made you feel, then I haven't written a keeper. And I always aim to write a keeper.
So, with those feelings in mind, what's your all-time favorite book?