Stories can have multiple layers.
So one of the question you should ask an author is if everything is working together.
One layer might be the setting in your story. This can be a town, house, special spot. The reader can become familiar with the place or might be already familiar with it because it is a real location.
Another might be the subplot of the book. This can add depth to the story by showing how others are facing a similar problem or bring relief in times of extreme stress during the main plotline.
Secondary characters also have a place in the layering of the story - they could be a start to their own book or show how the problems are enhanced or avoided by other people's lives or opinions.
Skillful weaving different layers throughout a book, an author creates a story that draws the reader into a new world and helps them understand the full scope of what their hero or heroine is experiencing in their lives.
Remember to make sure you have all of the layers connected in some way.
Some times it helps to create a list of each characters and write out what their goals are for the book.
Then see how they connect to your main plot,
if they create a secondary plot or subplot
how theses issues are resolved.
Play in the sand and see if you can make connection that you hadn't thought of before.
Hope this helps in weaving your story together.