✮ = I did not like the book. It was hard for me to engage in the story.
✮ ✮ = The book is good, but it doesn't leave me any sort of impression.
✮ ✮ ✮ = The book is somewhat enjoyable. It's not great, but it's not the terrible either.
✮ ✮ ✮ ✮ = I highly enjoyed the book, but it's not quite there yet.
✮ ✮ ✮ ✮ ✮ = The book exceeded my expectations! Definitely worth a reread.