I quit 11 YEARS ago.
I just decided enough was enough and I wouldn't be a slave to nicotine anymore.
The only REALLY helpful suggestions I could offer is that you have to make a lifestyle change in order for it to work.
If you always have a smoke with a cup of coffee...then quit drinking coffee temporarily.
If you associate being in a club with having a smoke in your hand...stop going to the club for a bit.
Smoking is an addiction, definately, but there are many habits that go along with it, that need to be broken too.
Breaking those associated habits is part of the key to breaking the addiction.