One suggestion: BE UNIQUE! (But don't be weird.)
It seems that everyone at my undergrad university is the president of some club, helped in some dental office, or ran a marathon for some benefit charity. Those are great things, but my suggestion is to find some service that shows your dedication (i.e., show longevity, not quantity), and your willingness to seek out your own, unique opportunities of service.
I was able to find a very unique niche of working with an often-overlooked community for over 500 hours. Not many people seek out their own opportunity--I really think that made me stand out (I don't think my scores really did🙂).
(I'm not trying to push numbers here to make myself better than another. I am not inflating anything--I have no reason to inflate since I've already been accepted. I'm just trying to help the person out who asked the question. Please take this comment in context of the question, and as no statement of showiness!)