You have already written songs of war and battle? Now imagine yourself the maiden who's beau is going off to battle, will he ever return? Imagine you are the mother or father of the lad. Or imagine yourself going off to battle, will she of the golden hair wait for you to get back. What would you say to her to guarantee that she would?

Don't worry if it's trite or cliched. It can always be re-worked later. Put your heart into it.