Creating a new chapter is always very different.  The chapter I'm currently working on in my sequel happens to be a long one and is taking a lot of time to get "just right".  I liken it to throwing hunks of clay on a table.  You just keep throwing stuff down, big pieces, little pieces...  in the general area you want them.  Then you start to mold it.  Scrape some away, refine some, smooth some, add a little here and there and begin to shape it.  That's what it's like to create this new chapter.  As usual, I thought I might be sculpting one particular object and it turns out to be something completely different, but more wonderful than I originally thought.  The story has a life of its own - I've learned to listen to it and create it exactly as it wants to be.  :-)