I quit cold turkey several years ago. We can’t smoke at work, I didn’t want to smoke at home with the daughter seeing me, so the only time I had a chance was when I’d go fishing.
I had about half a pack of stale cigs in my glove compartment that were about two weeks old. I lit one, promptly put it out and threw the rest away. Never lit another one since.
Some self-hypnosis also helped.