In his Lectures on Literature, Vladimir Nabokov offers this exercise for students:
Select four answers to the question what should a reader be to be a good reader:
1. The reader should belong to a book club.
2. The reader should identify himself or herself with the hero or heroine.
3. The reader should concentrate on the social-economic angle.
4. The reader should prefer a story with action and dialogue to one with none.
5. The reader should have seen the book in a movie.
6. The reader should be a budding author.
7. The reader should have imagination.
8. The reader should have memory.
9. The reader should have a dictionary.
10. The reader should have some artistic sense.
The students leaned heavily on emotional identification, action, and the social-economic or historical angle. Of course, as you have guessed, the good reader is one who has imagination, memory, a dictionary, and some artistic sense–which sense I propose to develop in myself and in others whenever I have the chance.
On the value and need of re-reading:
Incidentally, I use the word reader very loosely. Curiously enough, one cannot read a book: one can only reread it. A good reader, a major reader, an active and creative reader is a rereader. And I shall tell you why. When we read a book for the first time the very process of laboriously moving our eyes from left to right, line after line, page after page, this complicated physical work upon the book, the very process of learning in terms of space and time what the book is about, this stands between us and artistic appreciation. When we look at a painting we do not have to move our eyes in a special way even if, as in a book, the picture contains elements of depth and development. The element of time does not really enter in a first contact with a painting. In reading a book, we must have time to acquaint ourselves with it. We have no physical organ (as we have the eye in regard to a painting) that takes in the whole picture and then can enjoy its details. But at a second, or third, or fourth reading we do, in a sense, behave towards a book as we do towards a painting. However, let us not confuse the physical eye, that monstrous masterpiece of evolution, with the mind, an even more monstrous achievement. A book, no matter what it is—a work of fiction or a work of science (the boundary line between the two is not as clear as is generally believed)—a book of fiction appeals first of all to the mind. The mind, the brain, the top of the tingling spine, is, or should be, the only instrument used upon a book.
– Vladimir Nabokov on What Makes a Good Reader (Brain Pickings)