A hand shake is always an easy and safe way to greet people, however there are many professionals out there who are huggers and kissers, which can really get awkward.
While in high school there was a known cheek kisser who was about 25 years our senior (not creepy, I promise). Just one of those mid-western super nice types, don't know why he was in DC! One time at a formal event we saw "kisser " and went to say hi. My friend went to give the cheek kiss when, what do you know it, they both went to the same side....and lip kissed. Super awkward/hilarious to this day.
So is cheek kissing ok in the professional world? I do live where I grew up, meaning I see a lot of people in my professional world that I have known for a very long time. So yes, when I see them I do give them a good old cheek kiss. Most of the time this is at a professional networking event or a professional cocktail receptions. I think in those cases a cheek kiss is perfectly acceptable. I think it starts to become unprofessional when you are in a smaller meeting. If you start kiss cheeking people you know, it may make it uncomfortable for the people who don't know each other. Do they just start kiss cheeking everyone? Are you now the kiss cheeking whore?
I also think the industry you are in will depend on the cheek kissing policy. I wouldn't go to a CPA event and start kiss cheeking people, however in my industry of event planning, people tend to be a bit more up to a good cheek kiss greeting.
Moral of the story...make sure you turn in opposite directions.