I attended the Song School in Lyons, Colorado August 10-14. One of the instructors was Josh Ritter. Here are some points he made in his workshop, taken from my notes. In some cases, I've also expanded on his comments from my own experiences.
1. Why do you write? If you're not writing obsessively and for pleasure, then why are you doing it? You should be writing because you love it, you should be compulsive and obsessive about it.
2. There's no such thing as "Writer's Block". If you can't write, then don't. When you have something to say, you write. If you write all the time, eventually you'll run out of ideas. So you need to take some time off. If you force it, you'll write songs that you won't be happy with.
My comment: I need to start recognizing when I get to this point. When it doesn't flow, rather than try to force it, I should use my music time to improve my musicianship--learn new things on the guitar, piano or mandolin, learn songs written by others, take a singing lesson-- do some of the things that I never seem to have time for. All those things will help my songwriting and performance.
3. Originality: don't worry about it. Nothing is 100% original.
4. Cliches: never allow cliches in your songs. Our goal is to create new cliches. If you allow cliches, you're not pushing yourself.
5. Don't be afraid to kill your song. If it's not working, put it in the compost, let other songs cannilabize it. If you force it, it won't be a good song.
Another songwriter, John Common, uses the analogy of the junkyard for this. I like that analogy, too. If a song needs a carburator, go to the junkyard and take one off a discarded song.
My comment: I started learning this last Spring. My songs, "Me" and "Like a Child" used both lyrical and musical elements taken from other songs-in-progress.
6. Always keep a journal. Always record lines, ideas.
7. You don't have to be crazy to be a songwriter. Take care of the problems in your life.
My comment: for a long time, I didn't try to write lyrics because I thought I wasn't weird enough. I thought songwriters were born, and they wrote songs without effort. This prejudice held me back; kept me from becoming a songwriter. Or perhaps I didn't realize that I was weird enough to be a songwriter. :) And flowing from that concept...
8. Songwriting is a craft; it's hard work. To view yourself as an "artist" rather than a craftsman may take you down the wrong road. Songwriting is a craft, and occasionally we will make great art. Not everything you write can be great.
Josh mentioned that he typically goes through 8 or 9 drafts of a song. Then he plays it for people, and edits it some more.
To hear Josh's music, see joshritter.com or myspace.com/joshritter