I cluck at people, traffic lights etc. I don't ride a bike but when I'm on the bus I have found myself doing half halts and asking for left or right bend LOL. But I'm such a weirdo that these relatively small oddities go unnoticed amongst the very obvious talking and gesturing to myself... ETA
: Anebel, do you also give a jiggle on an invisible leadrope? I've done that once or twice!