I still remember my journey to quitting, I was a young woman and for my age a very heavy smoker. I had the hacking cough of an old gentleman and would without hesitation reach for a cigarette after a coughing fit!
There were 3 things only that helped me to give them up, and I made the choice at 21 on Xmas eve.
1) I had the misfortune of smelling my own breath after I had exhaled from a quick drag. I was talking to a lady whom I had a great deal of respect for, she was close enough for me to see the look on her face as she smelled it the same time as did I! That was my motivator, it was terrible!
2) I found holding and rolling a soft pen shaped object between my index and middle finger just where I usually held a cigarette provided a soothing comfort.
3) chewing and having something in my mouth, at the time I had long hair, after realising I was constantly chewing my hair ends I cut my hair short and swiftly moved to replace it by popping my long necklace in my mouth. All done subconsciously and once acknowledged I replaced again with my pen or pencil, while still unattractive it was much better than my hair or jewellery.
In later years I observed others giving up and I see it is easier not to tell other smokers you are giving up, without meaning to they often sabotage your efforts because they themselves don't want to be a lone smoker.
I gave up overnight, I went from 30 plus a day to nil. Never underestimate the power of your mind, if you can find the motivator, you will achieve it.