When it comes to quitting some people manage it first time - but many people have to try giving up more than once before they eventually succeed.
So if this isn't your first time don't worry. In fact if you've tried giving up in the past you've learned valuable lessons - about your will power, for example. What worked for you last time? And what did you find difficult? Think about these things before you stop smoking and you'll give yourself an even better chance of quitting for good!