I only smoked for a month or two in Uni, turns out I couldn't afford it and prefered to spend my money on booze. But in my job I am often required to help people quit smoking and these things I've been told are the most helpful -
A large part of the addiction is the habit of smoking. Identify the cues to these habits and remove them. To lots of people, it may be a morning coffee with a ciggie. If you avoid the cue (coffee, pub) the urge to smoke isn't there.
If you can't remove the cues, change the process of the habit. If you still want your morning coffee and to sit outside, you need to do something else with your hands and mind. Expecting that you can just do nothing, where before you did something that has a physical reward is a mistake and recipe for disaster.
Remove paraphenalia associated with smoking. Throw out your ashtrays, lighters and smokes of course. You are an ex-smoker now, you won't even need them again. If you have a seat or area outside where you always sit to smoke, dismantle it and change it.
How long until your first ciggarette of the day? If its not the first thing you do in the morning, you aren't really addicted to the nicotine, youre addicted to the habit. Don't bother with patches, gums or drugs. Go cold turkey.
I've heard that people find the following chart very inspiring to quit.