Reader Friday: How far do you develop your fictional world?

Our friend Basil Sands posed a question for today: How deeply do you develop the characters in your fictional world, and do you write about them beyond the primary works?

"I just put up a novella and a couple shorts that flesh out some of my main characters from the past four books with details that had been alluded to in those books," Basil writes. "Do you guys & gals do stuff like that? And when you do, do you keep it to yourself or put it up for the world to see?"

Tell us in the Comments!