What worked for me wasn't trying to quit smoking, but trying to replace my smoking habit with a vaping habit. Just the thought of quitting smoking caused anxiety attacks and a fear of failure so bad I'd be doomed.
When my vaping gear arrived I replaced all of my traditional smoking times/places/rituals with vaping times/places/rituals ... but in my opinion the trick was that even though I was really dedicating myself to vaping, if I wanted a cigarette , I'd have one. I wouldn't forgo my vape for a cigarette, I'd just have a cigarette after my vape if I still really wanted one. For example I'd always have a smoke after dinner out on the back porch, so I started having a vape after dinner on the back porch .... if I really REALLY wanted a cigarette .... then what the heck .... they are legal ... I'm a grownup .... I'd have one.
I went from a 1.5 - 2 pack a day habit, to taking me about 2 weeks to smoke the last half of a pack that were left when my gear came. When the left over ciggies were gone I just never had the NEED to go to buy more ..... if the desire ever hits me hard enough I'll just hit a few tokes on the VTR and decide if it's worth a run to the corner to buy a pack .... so far it's been almost a month and I still haven't visited the 7-11 on the corner.