There's an older guy who rides a heavy bike all over Lansing. He's kinda fat, and he's definitely not wearing cycling kit. Every time I encounter him, he pumps his fist in a circular motion--like pedals--and yells "Faster!--Faster!" This is with a big grin on his face, which is the complete opposite of bicycle stink face. Every time I see him, I get a big grin too, and for a few minutes I do ride faster.
For me, pumping the fist like cranks is the universal symbol for bike advocacy, and it should definitely be accompanied by a big grin.