I recently had a client who wanted to quit smoking but was not ready as he had a very emotive issue in his life. He wanted to quit smoking cigarettes but his partner had just left him. I think that you would agree that in most cases this is very emotional.
Now he could have come to me to quit smoking with hypnosis but the likelihood of it being effective I believe would have been quite slim. In this case his thoughts are taken up by the emotions of his relationship breaking down.
What I am getting at is that to successfully quit smoking you not only need to want to but you also have to be mentally focused and prepared. Where you have situations that are clouding you mentally such as anger, fear, panic etc the chances of quitting on a permanent basis are reduced considerably.
When you make the decision to quit smoking make sure that from a mental aspect you are fully present and focused. Visualise and feel how your life will be when you are a non-smoker. Build up a picture in as much detail as you can.
Look, it makes sense to ensure that you are going to be successful when you decide to quit so make sure that there are no mental barriers when you do the process.