I had a friend who quit smoking by allowing himself to smoke whenever he REALLY wanted to. Kept a pack in his car just in case.
Hasn't smoked for over 25 years.
Once I stopped I really stopped UNTIL rehab, over 9 years. Picked it up for about 3 months. The whole time I was aware of how crappy they tasted, unlike the first stint, where I felt more like MG. I just didn't buy a pack one day and that was that.