The process of writing songs is usually hard to define. Where does one start ? With the lyrics ? With the melody ? Playing an instrument ? Using a chord progression ? Reading a book or watching a movie ? And what impact does it have in the song itself ?
I don’t have any strict rule regarding music composition. I have had songs entirely written inside my head where I could listen to all instruments and others where I have started from the scratch. The Art of Music Making is indeed quite mysterious and sometimes even hard to define what is the catalyser of the entire process.
One of my favourites at the moment is to read a book or watch a movie and look out for inspiration for song titles and main ideias for lyrics. The main reason I do this is because a good lyric needs a good narrative and both a movie or a book can give you insights where and how to begin.
A great way to come up with some original work is to use harmonic ideas as a starting point. For instance like writing a melody in a specific musical mode (Lydian) or pickup a specific chord progression and create a melody on top of it
Anything can be a starting point of a song. A great way to write songs is to play an instrument even if not being good at it. The ideas you get for a song playing piano are probably quite different from the ones you get from playing guitar or drums. There are no rules to comply on this matter.
A song can also start from lyrics and a good idea is to have a note pad and write a list of words or topics you can look up for as an impetus for your songwriting creation. If you want to write a song about your fridge just do it. Maybe you can call it the Fridge of Love for instance 🙂