Creating Consistent Images for Story book

Hi!  I am attempting to create images for a storybook I've written. There are about ten different characters throughout the book. I want to make sure that the characters in each image I generate are consistent throughout the book. In other words, when Character "A" is one scene / image, in the next scenes, I want that character and perhaps another established character to have the same face, clothes, etc.  

How can I accomplish this?

Thanks!!