I don't really know how writing process happens, how these songs are arrived at. One of the things I like about the writing process is, I don't necessarily know where it's going, and even if I think I know where it's going, it'll turn out different. I find that exciting and rewarding.
I think it's absolutely possible to write a song and go somewhere where no one's been before, uncharted territory. In terms of content, I see limitations where there should be none. I know there are things I wouldn't write about, but that shouldn't be the case. You should be able to make a song out of anything, out of any situation.
The good part of writing is where it gets out of your control and turns into something else. You look at it and think "Whoa, where did that come from? That wasn't what I meant to write, but it's more interesting than what I was intending. Which part of my subconscious or my experience did that come from?" Often the answer isn't clear, and often the line between fiction and fact isn't clear, either.
Sitting around home I mostly play acoustic. I've got seven or eight guitars of various sorts, including a baritone. Sometimes at home, because a guitar is just lying around, that's the guitar I pick up rather than actually choosing something. I try to plan ahead for my laziness by leaving interesting things scattered about. If I leave a baritone guitar lying around, that's the one I'll pick up, and I'll start writing baritoney things.
I just like to entertain myself by sitting down and writing songs.
I think you can refine what you do, and become more consistent. And you write better songs that have a better shape and a better feeling. You evolve into and out of things, and go through stages, but, ultimately, you do improve.
As the writer, you're always a presence in the song. If you get close to what human beings are like, you're writing about common experience. We all do much the same things, so if you nail somebody, then you've also nailed yourself.