Fearlessness, absolutely. Discipline. You also need open-minded creativeness that lets everything in. You never want to lose a word or a phrase, yet every one should count. Always the best language possible. And, finally, knowing when to leave it alone. Stop when it's done.
People say, "How do you write songs?" I say, "Patience." I may have a track that's hot, but no words. I'll just let it sit for years, because I know they're going to meet. They'll find it.
I write songs and I sing them from the deepest part of my existence and I hope they connect with the deepest part of yours.
The advice I have for new artists is this - write great songs and play them live as often as possible. Get residencies all over town and crush it.