I smoked for a long time, like others here, and quit using the advice a book I can't put my hands on at the moment, but will try to summarize.

I cut down on the amount of nicotine I took in by smoking progressively milder and milder cigarettes until my Quit Day. I also stopped smoking in the house, so that I got out of the habit of smoking while talking on the phone, sitting at the table after eating, etc, and doing all the other things I associated with smoking. So, I had to go outside and purposefully smoke.

On the Quit Day I used everything possible. Some weren't so helpful, so I discontinued those, and some were, so I kept them up until I no longer needed to rely on them them.

One of the interesting things was putting on a nicotine patch on the night before my Quit day, so that I woke up not wanting a cigarette for the first time in years, since I had been dosing myself all night.

Things that helped were: giving up coffee. Not drinking alcohol. Removing all ashtrays, lighters and anything else that triggered the desire to smoke. Having something to do with my hands, such as mala beads to say mantras with, or Greek worry beads. Drinking water to flush out the nicotine from my body. Lollipop and Tootsie Roll suckers for oral gratification. After I had cut down on the strength of the patches until I quit using them, I had to rely on nicotine gum, (since you aren't supposed to use both at once) and tapered down on the dosage on that too until I had quit it.

Probably what helped most was that when I wanted to smoke, I remembered that that desire lasts for only no more than 5 minutes, and knowing that it would pass. I would breathe deeply and focus on the feel of pure, clean air filling my lungs, healing them and flushing out all the nicotine, formaldehyde, "tars" and gunk that I had been smoking.

Good luck. Persevere.