Feel free to download this list for future reference. The first line or two should hook the listener into wanting to hear what comes next. People will be able to hum the melody after hearing it a few times. The lyric is conversational. No forced rhymes, no convoluted phrases or sentences.
Meaning is more important.
This is the place where many songs fall down. I've seen songs where the title is never mentioned in the lyric, or it is a pick up phrase, rather than a strong line. The lyric and the melody belong together. It's called prosody. The words and music flow naturally.