I think the bottom line is to immerse yourself in the song, whatever that means for you. You have to become one with it, know the story, the emotion, put a bit of yourself into the song and make it yours. So if that means listening to a recording a dozen times over and over again, then do that. If it means reading over the tabs 3 dozen times till you remember the pattern, do that. If it means you just play the song on the uke over and over till it becomes second nature, then do that. OR DO IT ALL!! We all have our own learning style and you need to learn how you learn best. Some of us have photographic memories, some have 'audiographic' memories, some need to be hands on to learn, some by combining these styles. To maximize your ability to learn, hence memorize, a song, you need to identify your learning style and then perfect it. I hope this isn't too mundane of an answer and can help.
