I usually pull the clutch in and coast by if that's at all possible, level road or down hill etc, obviously not possible going up hill. I have even pulled over over turned off the engine and waited for them to pass in certain circumstances. Nearly all the riders I've met so far have either said 'thankyou' or put their hand up to say thanks

which is more than can be said for a lot of car drivers
I now do the above as much as possible after an experience I do not wish to repeat

Remember I have race can's fitted and as I passed a horse and rider giving them both a wide birth the horse got frightened and started rearing up, I don't know who was more scared me or the rider on the horse, luckily we both came out of it unscathed. So lesson learnt, horses do not like the sound of big V twins with no baffles
Chris.