For those who enjoy taking a look at how some books are illustrated here´s an example of one from some years ago.
Usually I don´t storyboard much but sometimes when a narrative is based on details that visually need to be constructed with abstract items like splatters for stars, the visual composition needs to be cinematic and work from page to page, etc, I tend to plan the book ahead shot by shot as if it was a movie.
This is a good example of what I do.  It´s all about the narrative and what a narrative needs and so each book presents it´s own challenges and needs different construction approaches so there´s not just one single method for me.
What follows is just an example of how was done for this one.