1 kiss on the cheek?
Everyone's greeting is different nowadays, so how do you know which one to whip out in those few crucial seconds?
The amount of times i've left someone hanging, misjudged the amount of kisses or hugged someone with one hand in theirs in an awkward handshake-hug combo...
If i had to write a greetings rule book it would be:
Same sexes should settle for a good old fashioned handshake.
If meeting for a second time and onwards, a hug.
Opposite sexes should offer an extend of the hand followed by 1 kiss on the cheek if wanted.
Upon a second meeting, a hug can be given instead.
Awkward waves are used if the distance between you is too great or obstructions are in the way.
Please note: There should not be in excess of 1 kiss EVER, it just gets complicated.
As for the farewell, handshake greetings are upgradable to a hug farewell.
Please note: This rule book is not applicable in many circumstances such as dates, interviews, the elderly... or pretty much any other circumstance than meeting friends. In such cases, good luck.