I use a lot of different techniques to help start and compose songs (and sometimes I am randomly inspired and let the music "flow" without any formal structuring or conscious thinking).

Here are a few of my articles on a technique called "Pre-Composition." This is one way you can compose songs and my students (myself included) use this technique and find it very helpful.

The Art of Pre-Composition #1 - http://www.guitar9.com/columnist525.html

The Art of Pre-Composition #2 - http://www.cyberfret.com/composition/kyle-hicks/the-art-of-pre-composition/part-2/index.php

Hope this helps and if any of you have questions/comments/etc, feel free to send me an e-mail at [email]Kole@Kolemusician.com[/email]