for me , the song / lyrics , comes to build it's self , and takes on the form as it is writing , like hobo , it starts with a word ,phrase whatever , a melody pops in my head and let the pen do what it does best , write , not think , and what it is , it is, bit that's just me , I write in pure emotion , as I am inspired and let that take me where it wants to go , know many writers ,put down their thoughts think of a "format" and then start to write , but really it is what ever works for the writer