I have just stopped for the third time in two years, here are my tips. I am a fifteen year smoker.
Nicotine replacement, try different types and see which ones work best. I stopped for 6 months using an inhaler. I am now using patches and the odd bit of gum
Change your routine. If you have a smoke after work then leave at a different time and go somewhere else straight away. If you buy a packet on the way to work then don't go near that shop!
If you smoke when out with friends then stay away for a few weeks.
Keep busy, play games, surf websites, clean house, paint walls, anything to take your mind oof it.
The cravings come in waves so try desperately to ride the peak as it will get less after a few minutes.
This is my fourth real attempt and it is the hardest yet. The one thing that is keeping me going is the knowledge that it will be even harder next time and all this pain will have been for nothing.
Think about sitting around with your loved ones in ten years talking about what cancer treatment you are getting and how scared you are of dying.
Think of how your parents/friends/partner/childr... will feel. This stuff kills fact.
Good luck and don't give up giving up!