stop going inside of gas stations. gas stations/convenience stores are a racket selling poison to poor people: gasoline, cigarettes, alcohol, candy, and salty food.
pay for your gas at the pump and leave.
the first step to stopping smoking is to stop buying cigarettes.
secondly, stop the routine. do you smoke when you wake up? on your breaks? in your car? don't. stop associating those things with smokey time.
if you're super hooked you can try to wean off with patches. you're trading one vice for another, but at least it'll help your lungs.
stop hanging out with smokers. find friends interested in pursuing sport and taking care of themselves. i sometimes feel bad that i've distanced myself from friends who waste their money/lives in bars night after night, but honestly it's for the best. you don't have to circle the drain with them.
my old man smoked from when he was 13 until he was 36, then quit cold turkey when they had me. that's probably one of the many reasons the man resents me but i digress: dude chomps gum like it's his job. it doesn't necessarily help with the nicotine cravings but i think it's a substitute for the oral fixation? i really wish i didn't just type a paragraph that had the words 'my dad' and 'oral fixation' in it, but cest la vie.
tldnr: stop buying smokes, stop hanging out with smokers