I smoked for 15 years. Went off with vaping for a while but gave that up too thankfully.
I found for me, what worked was little victories. Instead of thinking "how do I get through today with all these cravings", I used to think "this craving will last 5-15 mins tops. Just beat this one and go from there".
So I got lots of mini successes instead of one big success at the end of the day/week/month. Though I did enjoy those too.
I found if I got deep into a book, work, sport, guitar, etc I wouldn't notice any cravings and wouldn't even think about them. Literally forgot about smoking for hours at a time.
Experiencing forgetting about smoking was a huge confidence boost.
But for me, the biggest thing was just to beat the immediate battle/craving.
It's like the old saying - how do you eat an elephant? One fork at a time!
I'm about 7 years off them now and the only thing I miss is having the occasional spliff (even if it's a blunt/bong/etc, too risky).