Artists in all media tend to gravitate toward certain themes, topics and symbols in their work. Sometimes these themes are premeditated; in other cases they surface naturally over time.
Jorge Luis Borges routinely explored mirrors, time, and labyrinths in his fiction. Tom Waits and Kathleen Brennan are drawn to seedy characters and shadowy places. John Zorn has written over 500 tunes using traditional Jewish scales. Need I go on?
The great thing about writing is that it can be used to express just about any interest, hobby, or fixation you’ve ever had. The more you read, listen, observe, and experience, the more potential song material you have available to draw from.
Trust your intuition. You may not immediately understand why you’re drawn to learn more about lunar moths, but don’t let that deter you from reading, researching, and seeking out new moth-related adventures. Go ahead and give in to your own eccentric interests. Let them run amok. You know you want to.
Many writers and artists think you can’t force inspiration. In a way they’re right about that. Sitting in front of a blank page and straining probably won’t give you any brilliant song ideas (though it might give you a hernia). I don’t know of any way to snap your fingers and immediately receive an exciting, fully-fleshed, satisfying song idea.
But by being inquisitive, observant, and reflective, you greatly increase your chances of feeling “inspired”. Inspiration isn’t magic—it feels magic, but it’s really just the rush of recognizing a cool idea.
Nurture a habit of turning over rocks, reading books, listening to records, and observing people (including yourself), and I think you’ll find that this supposed “magic” happens much more often.
Trust your hunches. Investigate. Obsess. Reflect. React.
Once you’ve got an idea, it’s just a matter of craft—of shaping the raw material into a song and dealing with the challenges posed by that process.