1. Know the one big idea. Say the whole song in a short phrase — that's a strong title and chorus line.
  2. Verses tell the story with details you could see, hear or touch: who, where, what happened.
  3. The chorus sums up the feeling in simple words anyone could sing, and doesn't get ahead of the story.
  4. Put the title in the first or the last line of the chorus, and sing it more than once.
  5. The bridge says something new — a realisation, a change of heart, a look ahead.

Show, don't tell: instead of 'I was sad', show the cold coffee and the unanswered phone. Details let the listener feel it for themselves.