What are the cheek-kissing protocols in France?

Cheek kissing is ubiquitous in France among social acquaintances.

It's not a kiss as we know it, it's an air kiss. Your cheek grazes the other's and lingers for a moment while the lips make the kissing sound, without touching the cheek. It's OK to put your hand on your partner's shoulder but not to reel them in, hugs are totally uncool.

Women kiss one another all the time, men and women kiss but man to man is less common, unless it's a relative or you're living in Provence.

The number of kisses varies depending on where in France you happen to be.

One is maybe for cold-blooded Bretons, who might as well be English. Go for two, although three kisses is also common.

Which side to kiss first is important. Go left first, in other words you're kissing them on the right cheek, then switch to the other side.

If you get it wrong and end up lip-to-lip you can laugh it off to show how droll you really are, which is just as important as being a correct kisser in France.