I've learned that people are surprisingly friendly if you say "Good Morning!" as you ride by while they're out walking.

At 4 way stops, sometimes oncoming cars think my left turn signal is me giving them the ok to make a right turn ahead of me. Now I look right at 'em (if they have a right blinky going and it really should be MY turn to go) point at my chest, then point to the left.

Then I wave and mouth "Thank you" as I go through. (even though it really was my turn anyway)

Cars pay MUCH more attention if there is a motorcycle cop riding along side you!!! (two-wheeled solidarity!)