The worst song lyrics are heavily literal and dependent on adjectives, e.g. (using the example of a love long) “She’s hot. . .”
Mediocre song lyrics use similes (“X is like Y”), e.g. “She’s hot like the Texas sun. . .“
Good song lyrics use metaphors, e.g. “Sunlight on the first day of spring. . .”
Great song lyrics use concrete, specific metaphors, e.g. “She wore the light of a thousand burning suns . . .”*
*This one borrowed from a Holly Arrowsmith song.