You can get a pretty poor element fishing from the pontoons sometimes, but like all humans they will generally respond to the way they are being treated themselves.
As much as they pi$$ me off not moving, I always make the coming alongside intention very obvious and definite (you've got to take ownership of the berthing space), by calling it out on approach, then ask if they are catching anything during the tie up process.
It seems to calm them down acting in a friendly sort of way, and takes the sting out of the aggressive ones.
As said before, watch the groups of early 20 year old blokes with cartons of cans around.