Every story makes a promise to the reader. Actually, two promises, one emotional and one intellectual, since the function of stories is to make us both feel and think.

As a writer, you must know what promise your story or novel makes. Your reader will know.

Readers want to see, hear, feel, smell the action of your story, even if that action is just two people having a quiet conversation.

The reader is going to imprint on the characters he sees first. He is going to expect to see these people often, to have them figure largely into the story, possibly to care about them. Usually, this will be the protagonist.

To me, at its best, that's what art should do, perform both the emotional and intellectual function.

Keep every promise you make and only make promises you can keep.