Make A Big Sign: with some variation on the words “FREE COMPLIMENTS AND POSITIVE FEEDBACK”
Roll up some cardboard to make a cone, or buy a cheap bullhorn.  Say nice things to people on the street.  No irony, no sarcasm.  If people talk to you, be warm and understanding – see them for who they really are and for who they dream of being.  If they are critical of you or just downright mean – heckling or shouting at you – appreciate their enthusiasm.  Say “Hey, I bet you could really do a lot of good if you focused that kind of energy into your passions!”  Encouraging the good within them.