I think no single method works for everybody. My method for learning lyrics was pretty ponderous but successful for me. My method was to write out the entire song in long hand first. If I knew the chords I'd put in slashes for the beats and learn the chords and rhythm first. Next I'd learn a line and then the next. Sing and repeat line 1 and 2 and then add line three until I had them learned and so on. Once I had the verse down I sing the first verse and then the first line of the next verse or chorus but I always sang the entire collection of lines preceding the next line in the song I wanted. This reinforced the memory.

I'm sure everybody else has a different method.

Don