When you are preparing for preaching, one must edit the sermon. One must take a very close look at the sermon and rewrite it. Henry Mitchell has written a very important article on this very subject that you can find in Best Advice for Preaching. I would encourage all new preachers to get this book.
Before you are ready to preach a sermon, you should edit and polish your sermon. One of the few articles that address sermon polishing is Henry Mitchell’s. He has written a in the John McClure edited book Best Advice for Preaching. I generally speak of editing and polishing a sermon in terms of 3 edits. You might look at each of these edits as a different dimension of a comprehensive edit of the sermon manuscript.