I stopped smoking by not buying any cigarettes.
No fuss.
No nonsense.
No hyperbole.
That is all.
I quit alcohol in the same manner, just under 5 years ago. I did scare myself into it, though

. One afternoon, I was starting to get stuck into my usual run of drinks, and felt uncomfortable in the chest. My liver felt like it was about to reprise the chest-bursting scene from
Alien, and my heart was pumping extremely heavily. I poured the remains of the drink in the kitchen sink, and didn't touch another drop of alcohol that day or any since. I hardly got any sleep that night, either, and am convinced I was very, very close to having a heart attack. A check at a local GP showed my cholesterol was 9.5 and blood pressure about 200/120, and I was 20kg overweight and unfit.