At the massage school where I go for massages, you aren't even *allowed* to tip. School policy, since they're completing the X number of hands-on hours they are required to have to complete the program. Not sure if that's the case at the school you're going to for your massage, but could be! At mine, they have a notice at the check-in desk stating the policy.
I got a massage at a school last month. I was charged $35 and I gave a $5 tip. I asked about tip policy when I made the appt., and they said it was optional.
I need to go to bed. I read your title and imagined going to a school-school (like a high school) for a massage and wondered what kind of fundraiser is that?! Duh.