I was a very addicted smoker for over 30 years, never without a cigarette and always planning my next opportunity to smoke. I quit in 1986, by using a book on self-hypnosis written by a doctor, and by using all the behavior-modification tips I could round up. I never smoked again.
On thing that smokers need to remember: You will quit eventually. Will it be like my sister, who quit when she was hospitalized with emphysema? Maybe it will be when you have a heart attack and then a quadruple bypass, like my other sister. Perhaps it will be like my friend's mother, who quit after her diagnosis of stage-four lung cancer.
My impetus to quit was seeing a friend hooked up to chemotherapy for his lung cancer. I knew it was time for me to face quitting. I'd never tried before, just thought about it but justified continuing to smoke.
So…. if I'm allowed to, I would recommend the book I used. It's out of print now, but used copies are sometimes available second-hand on-line.
I also would like to post the behavior modification tips here, when I've got some more time to type. One of the most important tips I got as I began the process of quitting was in a magazine article, saying that quitting smoking is like the death of a loved one. Your cigarettes are your friends and are always with you. When you do quit, you must think of them as you would a loved one who has died. You miss them horribly, you think of them every day, as time goes by you miss them less, but they cannot come back, no matter how much you wish they could. This helped me with quitting smoking; the cigarettes have died and gone forever.
Post #2: Here are the behavior modification tips I used to quit smoking after 30 years of total addiction. I used a book called "A Doctor's Book on Smoking and How to Quit," by Dr. Anthony Colby. It's available second-hand sometimes, as it's out of print. It's a 14-day plan to quit. Each day has a "practice quitting" session and some relaxation ideas.
Once I made the decision to quit, I put an X on my calendar for the day I'd start the book. (I used my birthday, which was about a month away.) From that day on, I never bought my cigarette of choice again. I bought one pack at a time of anything else, including menthol, Camels, weird brands, etc. By the time I began the book and the process, everything I was smoking tasted terrible and I realized I was just smoking to smoke.
I got a large glass jar and filled it with water, then emptied a few ashtrays into it. I kept that jar on my dresser and looked at it and smelled it often.
I rewarded myself, putting the cost of cigarettes for one day into a little plate in my room. Each day I counted the money, and every five days or so I spent the money on myself for a reward. I kept this up for a while afterwards, always reminding myself how much I'd spend on smoking.
I told everyone I knew that I was quitting. I got support from ex-smokers and present smokers, and it would have been much harder on me to start smoking again and face them. People will be very proud of you.
I carried a large baggie in my purse for months, with hard candies, mints, gum, lollipops, to have something to suck on instead of a cigarette. There were calories, but the effects were certainly better than smoking. It was worth the few extra calories.
I convinced myself that if I should ever pick up one cigarette and have one puff, I'd go buy a carton and start the addiction all over again.
Walking by people who smoke after I quit, I realized that this was how I had smelled. It was on my hair, my clothes and my breath, in my car and in my home.
After the first few days without smoking, my hands and feet began to feel like I was putting them in an oven, just a reminder of how bad my circulation had become. I only wanted to quit once, and it was difficult of course. I cried and went through the grieving process, as something I loved had died and gone forever. I knew that I'd miss them less every day, and that I'd learn to live without them. They couldn't come back no matter how much I wanted them to, just like a loved one.
Anyone thinking of quitting, please try everything you can to make yourself successful. You'll be making the decision voluntarily, rather than having it made for you by the medical profession.

I hope some of my tips help. The very best to everyone who decides to quit.