One of the greatest social proof tactics involves people who are eavesdropping. Catch them and be friendly, incorporate them into your conversations. AMOG them gently so you can defuse them as obstacles, but still keep them around as friends or social proof otherwise.
Example:
You're talking to some girl next to you in class, and a few guys are listening in.
To the girl: You should say Hi to those guys, they seem like they're really interested in our conversation.
(You've just AMOGed the other guys by immediately telegraphing their needy/interested status. In addition, you have incorporated them into your conversation, so you have the opportunity to use them to show DHVs)
-Damian