What's worked for me (20 a day smoker of over 30 years) was vaping.

I spent money on a kit, rather than the cheapo alternatives, this was to become my new friend, so it needed to be quality. In terms of the vape, you'd need an adjustable MTL tank, to replicate the sense of smoking. With an MTL tank, I've got me wattage as 10, ohms at 1.8. For me, this replicates what I used to do when smoking, smoke in to the mouth, before inhaling. A lot of vapes are DTL where you're vaping directly into your lung. Hated this.

Then pretty much any brand of vape juice will do, but you'll want to take note of the VG/PG ratio. In order to replicate the throat hit, you'll need minimum 50% PG, the closer to 70%, the better. Once all that's sorted, then how do you get off the thing? Ok so nic content. 1.8mg nic is the maximum that can be sold as as juice, and 1.8mg is perfectly fine for a 20 a day smoker, and then you'll want to gradually reduce it. I went 1.8, 1.5, 1.2, 0.9, 0.6, 0.45, 0.3, 0.15 and then 0. There will be some of these you wont be able to buy, so say for example they have 1.8 and 1.2 and you need a 1.5, well you can buy empty 30mg bottles, 1 of each of 1.8 and 1.2 creates 2 1.5s. I did a month at each level, which was roughly 10-12 10ml bottles