1. Get very, very clear that you want to quit. Meditate on cancer and other such things. If you do not want to quit on the deepest level, you will continue to smoke. You have to WANT to quit, really, or you're wasting your time. If you really DON'T want to quit, it won't stick. If you want to quit it's really not that hard. There's all sorts of things you can do to help you - read about the health effects of tobacco, smell ashtrays, look at photos of tumours. Hell, I even spun a Reveen record on quitting smoking. Whatever helps, helps. Get clear that you want to quit.
2. Use your anti-corporate rage to help you; cultivate anger at the fact that you are paying tobacco companies to kill you slowly. How stupid is that?
3. Do breathwork. The Breathing Book by Donna Fahri is good, or do any yogic breathing exercises, deep relaxation, etc. Get in touch with the part of yourself that you are polluting. Sex, since it also involves deep breathing, is useful, too. Long walks in fresh air.
4. If possible, switch to a very, very pure brand of tobacco - American Spirit or something with as few additives as you can get. I'm pretty sure it helped me a lot to quit that I moved to Japan around the time I stopped. Even just a change of tobacco might have helped; I wasn't "as" addicted to Japanese tobacco.
5. Don't mess around with nicotine gum or e-cigs or such. These may be fine in and of themselves, may have advantages over smoking, but don't think you're "quitting": you're not quitting the drug, you're just changing the method of delivery. If you want to quit the drug, you have to go cold turkey for some period of time. Don't be dumb about it; taper off - go to ten cigs a day, then five, then three, before you wake up to your first cigarette-free day. But you won't be able to avoid a certain amount of discomfort if you're trying to quit. It's part of the deal.
6. Plan ahead. Be prepared for a few days where you feel like hell, and give yourself the time and space to feel like hell. Don't try to do the cold turkey part when you have stresses or responsibilities, or you're setting yourself up to fail. Use a long weekend or such, when the holiday is on Friday, so the Friday is your first day totally without. By Monday, you'll be coping a lot better. Saturday and Sunday, relax at home, treat yourself very well, and avoid anything that causes you anxiety. Yoga, sex, breathwork, fresh air, relaxation... all very helpful during this time.
7. Avoid the company of other smokers for as long as possible when quitting. You will be tempted.
8. Stay in the moment, deal with each craving as it comes. Rather than thinking, "I'm never going to have another cigarette again" - which increases the pressure on you - think, "I can have a cigarette again any time I want, I just don't want to right now." And ride out that craving, and the next. If you focus on each separate battle, it makes it much easier to win the war.
9. Do not think you can allow yourself "just one cigarette" - first off, you'll feel sick as a dog when you smoke it, and secondly, it will PROBABLY lead to you going back to smoking fulltime again. Every unsuccessful attempt to quit begins with the "I'll just have one every now and then." If you're a nicotine addict, it won't work.
10. If you screw up, don't feel too bad. It's hard to quit. Just take what you learned from the experience and try again. Eventually you will quit...!