I think the starting point for writing a song varies hugely depending on your personal strengths and preferences. Musicians will probably come up with chords and melodies first, while lyricists will come up with words first.
My personal approach swings between the two, sometimes I have a great chord structure and the melody sings itself, sometimes I know what I want to sing about and the musical part takes a bit more time. I can find inspiration from a drum beat or a bass line and sometimes I am inspired by someone tinkering on the electric guitar.
I’m currently writing a new song, in the next few weeks I’ll share my song writing journey with you.