Some of them have come to me quickly, just about in one whole finished piece. Like one that I wrote in my head as I stood up to my kneecaps in a lake at sunset, and then wrote it down on a paper napkin in the car on the way home so I wouldn't forget it. It's called 'Angels of the Wild', and it's probably the one I'm most happy with.
Some take a lot of struggle. I have a folder of parts of songs, and song ideas. I have tapes lying about with parts of songs or tunes I have sung or played into them.
Some are written as a way to work out feelings, such as one I wrote when I heard a close friend of mine might be moving across the continent.
Some are written out of need. The songs I write for my Music For You and Your Baby classes are like this. I may add verses, or put lullaby words to a nice tune, or write something on a theme.
A few of us are starting a song~writing group here. First meeting is this weekend.