Switch to a cup of herbal tea whenever you usually have a cigarette
The act of brewing the tea and slowing sipping it as it cools will provide the same stress relief as a hit of nicotine. Or carry cinnamon-flavored toothpicks and suck on one whenever a cig craving hits.
Instead of a cigarette break at work, play a game of solitaire on your computer
It takes about the same time and is much more fun (although, like cigarettes, it can get addictive). If your company prohibits games like that, find another five-minute diversion: a phone call, a stroll, or eating a piece of fruit outdoors (but not where smokers congregate).
Picture yourself playing tennis
Or go play tennis. British researchers found volunteers trying to quit smoking were better able to ignore their urges to smoke when they were told to visualize a tennis match.