The wrong way is to approach any expressive art form as being right or wrong.
If I want to write a song about a car crash...it could be happy...maybe I'm happy it wasn't me, maybe I didn't like the person involved in the crash, maybe I'm sad, possibly because it wasn't me in the crash, maybe it was a good friend in the crash...maybe angry at the person responsible for the crash...etc
To state there's a right or wrong is to invalidate the humanistic element that gives any expressive art context and meaning.
We're getting off topic here, but since I was one of the posters who first used the word "wrong" ...
You use the term "expressive art." ALL art comprises at least two things: Inspiration, and technique, or craft. One of those two without the other is not art.
You may love your three-year-old child's drawings, but chances are it's because a) the child is yours and you love even her poop, and/or b) it expresses a child's refreshing outlook on her world. But the child will need to learn how to color within the lines - technique - before she can produce art.
It's no different in music, and, truth be told, most of us are happy to be craftspeople. There's nothing wrong with that aspiration!
Your example of writing a song... almost anybody can write a song or a poem. Writing something artful requires craft - meter, rhyming, word choice, harmonic, rhythmic, and melodic choices.