One small tip is that you must make a commitment: Decide to give up instantly and flush the packet in your pocket. You have then made that commitment.
I never smoked much at work but liked a smoke with a drink. I'd buy a pack for the night and give it away before I went home. That became one of those small cigars and then none. Ten years later I was getting a ragging from the smokers I was drinking with so had one, it was terrible. The smell on my hand meant that I had to drink left handed.