Just a quick thought on songwriting; After having written well over 100 songs (maybe 200) I often wonder to myself what is left to write about that is not a repetition of something I've written before? What is left for me to write about?
One answer for me is to write what I care about. If I care about something, I am easily motivated to work on a song expressing what I am thinking and feeling. It is fine if you are unsure how you feel; that can be what you say in the song! What you should not do is write something you know is untruthful of ridiculous just because others have written that or believe that. Do not go for the comfortable orthodoxy - unless you understand it, are informed and really mean it.
My second answer to the question of "what should I write about?" is also fairly simple; tell a story. For me the story should be true-to-life or be a story that contains real truths even if the events are fictitious or even fanciful/magical/science fiction. The story should have a point beyond random action.
My two rock operas have followed this path; the first rock opera by UniversalDice "My Name is Thomas..." told a story of faith and reason and life and death. It allowed me to express things that were on my mind at the time and the storyline made the subject matter easier to dig into.
Our current release, "birth, love, hate, death" is a love story and enabled me to write songs about romantic love, a topic that has always been difficult for me since I've always been intimidated by the fact that it felt like every possible love song had already been written. By incorporation love songs into a storyline, I was able to say some things that, hopefully, are new and enlightening to the listener.
It would be really good if you visited our Spotify page and follow us there; http://www.universaldice.com/spotify/
or our "birth, love, hate, death" page on YouTube: https://www.youtube.com/playlist?list=PLDzwgiI-BVobZER3kiWxPtZne0rne9Hoz