Here is the PDF of a presentation I give at songwriting classes from time to time. The method is primarily used for "Story Songs" but can be applied to other types of songs as well. The whole idea is that a songwriter should spend a lot of time working with more ideas before deciding on which songs to actually finish. So at any one time, I might have 50 ideas that I'm "sketching" out. And then every so often one rises to the top and I decide to finish it. Also, here is a related paper I co-wrote and was published in the Music & Entertainment Industry Educators Association Journal. It argues that you can pretty much take any pop or country lyric and put it in one of four categories -- based on the levels of narrativity and semiotics.
Drums On Demand, Inc.