I smoked for 30+ years until quitting about 4/5 years ago.
During those 3 decades I had tried many times, once I did not smoke for a whole year.
What would bring me back were the bars. I think the difference with the last and so far successful quitting was that you cannot smoke anymore in bars and I do not get tempted when I am drunk and weak.
When I quitted I was smoking a full pack every day. I stopped suddenly, just did not buy anymore cigarettes after I smoked my last one.