One of the first reasons should should relate to health. Do not rationalize and tell yourself that emphysema or lung cancer can never happen to you. Lung cancer can happen to people 20 years after they stop smoking, and it can happen earlier to those who never stop.
Pick up a note pad, pen or pencil. Sit in a quiet room and jot down all valid reasons that you should and could stop smoking. There are probably more than a dozen sound reasons, (one of them being the cost), but 12 steps should be more than enough to convince you to stop.
Add fruit slices to water.
Make up your mind that you can and will stop smoking. Think of things to do each time you have the urge to smoke. Buy hard candies and put one in your mouth instead of a cigarette. Buy lollipops for the same purpose. You might gain weight during the process, but you can work on losing it once you stop smoking. Drink plenty of water; add a slice of lemon or orange if you do not like plain water.
Find a self-help group for those who are "kicking the habit." If there are none in your vicinity, start one. Run it similarly to Alcoholics Anonymous, advertising by word of mouth and posting fliers inside stores and schools. Start a buddy system for members to to assist each other when the need for a smoke becomes overpowering.
Keep reading the 12 steps you wrote down. Add more steps if needed. Be determined, and you will be able to stop. The first day is the worse, with each day getting easier. At the end of the week, you will find that food tastes better, your breath smells sweeter, you have more energy and you feel better. Don't waver; remember, you do have control of yourself and your actions. Once you make up your mind to stop smoking, just do it.