I think one thing you do so well is to carry metaphors as long as possible without dropping them. Does it start with a metaphor, or do you start with an image and build it out?
I think probably you’re right that it often starts with a metaphor, in that a metaphor is relating one thing to another – the clouds look like cotton balls. You’re relating. At the center of every song I’ve ever written is the relationship between something and something else. It’s a catch-22 when someone asks me what a song is about because you can’t point at it. It’s a bridge between one thing and another thing, most of the time.