Bedtime stories

When I was little, my mom and dad made up stories at bedtime for us.  I loved listening to their stories.  Now that we have kids, I've wondered if they planned the stories ahead of time or just came up with them on the fly because I've learned how hard it can be to come up with them.  During Cory and Ellie's preschool year, they wanted me to make up stories every single day on the way to school.  I was able to come up with good stories for a few weeks but after awhile felt like I couldn't come up with something new and interesting every day.  At that point I started retelling fairy tales.  The kids had favorites and those I would tell over and over.  If I ever forgot even one detail they'd fill it in for me.   
Now we mostly read books.  Jason is gifted at reading and telling stories.  He gives the characters interesting voices, pauses at all the right moments, and doesn't need every story to have a moral (like his wife does).
A few nights ago we started a new book.  It's called Sir Fartsalot hunts the booger.  Our kids think it's hilarious.  I picked it in an effort to get Toby reading books at or above his reading level, rather than the super easy books he picks out at the library.  We still haven't finished it so I can't say whether I think it's a book worth reading yet but so far we're enjoying it.