My advice would be, make a real consious effort and use a systematic process. Smoking is addictive on a psychological and chemical level, so, here's what you do.
For the psychological part (I'm not sure what your exact motivation is for quitting-- a good one is your health though). Google around and find some stories and or pictures of people who have or have died from lung cancer from smoking cigs (The Marbloro man and the CEO of Marbloro are a couple that come to mind). Really make it sink in how bad smoking is for your health and how much pain and suffering it could cause you down the road--- this can give you strong psychological incentives to kick the habit.
For the chemical part, do it, as somebody else suggested, on a gradual basis-- to be successful though, you'll want to use a real structured and specific system. #1. Figure out exactly how many cigarettes you smoke a day (it may change day to day, but just take some day- tomorrow, as your exact model to improve on).--- #2.Get a special journal or notebook to write this down in---- every day, write down exactly how many cigarettes you smoked, and then write down exactly how many you will smoke on the following day.--- You can map this whole shart out tomorrow (or today if you know how many cigs you smoked exactly)--- every 3 days drop a cigarette, do this every 3 days on the chart or calender until you aren't smoking any.
Now you have it mapped out. Write it in a journal or a calender, hang it on the wall or the fridge or the door (where you will see it regularly)-- and finally FOLLOW through, and DO NOT deviate from the plan you chart out. -- If you have to look at pictures of people dying of lung cancer, or if you have to go to the hospital and see them face to face in order to reinforce your motivation to quit-- then do it.
Anyway, that's how I would do it, in my experience, you can't approximate that you're getting better about breaking a habit, you have to take specific and well thought out steps to be successful.
Good luck bro..