I do a couple of different things when I'm writing a song.
First of all, I try to figure out what the song's about. Is it a song about a topic (for example, politics or religion), is it a song about a person's struggle, or is it about a relationship? If you can pinpoint what you want the song to be about, it will help the words come faster. I tend to do some free-form associations on another piece of paper so I can work out some ideas in this arena.
Secondly, I try to come up with a title. That may sound like a pretty simple thing, but it helps. I personally try to make sure that the title isn't something totally out there. If you can fit it into your song's chorus, then all the better. It'll give people a strong hook that they can grab onto both lyrically and musically. It's kind of like home base. Here's a
song that I wrote where I came up with the title first. It was a stray phrase that I came up with while walking to a concert in Washington, D.C. that stuck with me.
Next, I try to come up with at least one or two stories that try to convey what I want to say. I'm a guy who relates to stories in songs. It helps the listener relate to the characters. In "Pigeon of the System," I used two different characters, telling short third-person stories as my verses. I've also written songs where there was just one character telling a first-person story. It all depends on what you want to get across.
Next, I start writing the lyrics, developing a melody that feels natural to the words as I go along. This is usually where I sit down and try different chord progressions, too. I let the melody come first, though, and that's shaped by the words. So the chords are For the first verse this is pretty easy. It gets harder as I add verses, though, because I feel strongly that the melody should be the same throughout all the verses. Some songwriters change the melody to fit the words they want, but that always sounds unnatural to me. If the words match the melody all the way through, it doesn't sound forced to the ear. By the same token, I am very adamant about getting the same number of lines in my song. In Western popular music, people are listening for resolution. The writing of the song should seek to provide both lyrical and melodic resolution all the time.
So, after the choruses and the verses are done, I tinker with a bridge if I feel the song needs one. For me, this tends to present the main thrust of the song in a different light. It just reinforces what the main song is about.
I tend not to write instrumental sections into my songs. I occasionally will have a chord progression that can be soloed over, but I feel the performers should have as much freedom arranging the music as much as they want. If they want a solo of some kind, the verse chord progression usually provides enough harmonic diversity to act as a palette.
Finally, I come up with a little closer or coda to end off the song. This could be a couple of independent lines or a modified chorus. Again, just something that provides resolution.
One other thing I'm mindful of is this: Sometimes you've got to break your own rules. I don't always start by asking what's the song about. I don't always use the title in the chorus. It's kind of like what my theory professor taught me in school: learn all the rules and THEN start breaking them. So, that's what I do. And I sometimes I get really good results that way.
I do have to admit, that I'm in no way as diligent about songwriting as I want to be. I have to try little tricks to make sure I do it. For example, I typically write with a guitar, so I try writing songs with cut capos and alternate tunings to give me more harmonic variety. I picked up the 'ukulele because I thought it had a nice sound that I could use to give myself some harmonic diversity. Also, I try to do something every year called
February Album Writing Month. Last year was my first, and it wasn't very productive due to outside obligations, but I did get a few songs done. And anytime you get a song written, you succeed.
OK, that was a bit long-winded. I hope it helped, though.