To each their own when it comes to smoking. For me, it's a habit I picked within the last year that ended up helping me with pick up.
Everyone seems really caught up on the whole alpha/beta thing which I understand, but smoking doesn't really fit into that at all.
Smoking is a 'reset' I use when I go out. For me at least, when I go out to have fun, a lot of times I just need a change of scenery to get my mind straight and make sure I stay engaged socially. Its easy to run into the habit of talking it up with your buds at the bar when that's really the last thing you want to be doing.
The worst thing you can do is be the guy just standing there doing nothing though. When I find myself there, even for a split second, I know I have to 'reset' my situation and state of mind. To do that, I have the options of:
1) Grabbing another drink - getting tanked isn't the best way to be on your game and yeah, grabbing another shot might boost you for a few minutes, but it could send you off into the deep end and all of a sudden your up the next day going, "what the hell did I do with my night?" I will say that landing a spot at a corner of the bar and milking your drinks can be effective. Its a high traffic area and an easy way to start conversations if you are feeling social.
2) Going to the bathroom - What are you going to do in there, talk to other dudes?
3) Dance floor -
Going out for a smoke is really the easiest reset there is. Smokers seem to have this sort of unspoken bond, it's hard to explain. You go outside for a smoke and the easiest way to get into a group you want to associate with is by bumming a cig/asking for a light. If there is a girl in the group you want to start a chat with, it's much easier to do so after initiating with her or someone in the group after asking for a lighter versus walking into a situation blind trying to start something out of thin air.
I forgot where I read about the whole reset thing on here, but that stuck with me and since then I've realized my best nights are when I'm in never in one place too long. Smoking is part of that for me.
It doesn't have to be for everyone though, so if you don't smoke I don't suggest starting, but if you smoke already, use your bad habit to your advantage.