it's possible for a songwriter to be too 'clever' in his/her use of words, or literary references, or whatever. These will appeal to some people, but if you are aiming for wider success, keeping it relatively simple is a good idea.

Tom Lehrer has a perfect example of this when introducing one of his songs with the story about the young necrophiliac who gets his dream job in a local mortuary. He completes the story, after a pretty weak audience response with 'the rest of you can look it up when you get home'... which got a bigger laugh.

As for the original question... experience, observation and an intimate relationship with language.

LTS