How often? Have you ever considered about quitting?
I haven't smoked at all in the past month or two because of immense school work.
I don't consider smoking as something that you "quit". Just like you don't need to "quit" from taking long walks to clear your head and figure your emotions and thoughts out by yourself. For me, smoking has that effect as well, smoking has many good effects to me and doesn't hinder my ability to do other things while on it (like drinking/being drunk). It takes away my anxiety problems which I have a bit of.
But I smoke whenever I have the desire and the time to, on my own schedule, some months I smoke everyday, some months I don't smoke at all. It depends on if I think I need it. So I can't exactly tell you how often. But it's great for socializing, so during the less busy time of the year, when I socialize a lot and go out with friends, I'm usually high everyday :)