I smoked a pack a day for 25 years and gave up this past New Years Eve. Haven’t had one since.
My secret? A rubber band! Put it around your wrist and when you feel the urge, pull the band, let it go and give yourself a zap. It works because normally you have the urge and you give into it with a cigarette. So the urge is associated with pleasure. However, giving yourself a zap on the wrist associates the urge with pain. The urges, when they do come are a lot shorter. Deep breathing helps too.
Good luck to anyone who wants to quit.