On a spray bottle/can etc, I turn the nozzle so it facing the same way as the "front" (label side) of the can.
You could be a geisha. We had one a few years ago in Kyoto, they'd pour your beer for you and then turn the bottle so it exactly faced you. We were drinking out of opaque cups as well, but they could tell when you'd emptied your cup and needed a refill.






