I quit for two years. I could have remained a non-smoker, but I enjoy the habit (and to onlookers, spare me. I'm not kissing you and women will tolerate it if you have other positive attributes) .
I smoked from age 16 to 52 (two packs a day of "full flavor.") To no longer have the craving or the thought, it took about a year and a half, but this works.
I started vaping. I bought "tobacco" flavored juice.
I started with the same nicotine equivalent (I think it was 1.8). I vaped this for a few months and then when down to 1.6. They actually do not make a 1.6 and so, I mixed 1.2 and 1.8 into a separate bottle to make a 1.6 version.
A few months later, I went from 1.6 to 1.4. Again, they do not make a liquid to this level. Once again, I used a separate vape bottle (one that had already been used) and concocted my 1.4.
A few months later, I bought a 1.2 over the counter, then months later, it was 1.0, then 0.8, then over the counter .06, ,then .04, then over the counter 0.3
This part took about six months. I then would by 0% nicotine and split in in half with a 0.3%. Then, I'd use the 1&1/2 percent and spilt it with a 0 percent nicotine juice. After that, I went for about two months (totally psychological) vaping at 0%.
At this point, the nicotine is out of your system. Although you may have the habit of vaping (just like a cigarette) it's easier to put down. Eventually, you don't think about lighting up very much and then with each week, the thoughts become fewer and fewer.
If you want to quit, this will work. When I started back, it wasn't from a craving. I just simply (despite the social stigma) enjoy smoking. The only reason that I quit in the first place was to prove to myself that I could.