I was doing some research on smoking 'cause a friend was starting to smoke and I was trying to discourage him.
There was a large study done in a British medical journal of teens 14-17. They asked them if they'd smoked ever, if so how often, did they plan to continue to smoke. The really shocking results were as follows.
A significant portion of the people in the study smoked once or twice per month. Nearly all of this group said they did not plan to become regular smokers. Yet when followed up 3 years later, almost 90% of those who smoked only once or twice per month had become regular daily smokers (half pack a day or more.) Of those, about 80% said they planned to quit within 6 months.
In a followup two years after that, of the same group (smokers who planned to quit in 6 months), 70% were still smoking, most had tried to quit at least once and failed.
Cigarettes have been shown to be more addictive than heroin. The tobacco companies have spent billions of dollars engineering their product to be as addictive as it's possible to make it, this has been proven. Trying to beat out the best minds in the industry who have engineered the product in order to ensure you become addicted is not likely to be a successful battle.
More than 95% of the people who smoke more than a few cigarettes will become addicted smokers. Nearly every single person who is an addicted smoker will tell you they never intended to become smokers.
If you start smoking, even very occasionally, you are very likely to become addicted. There are a tiny handful of people who have not, but statistics say you will probably not be one of them.
I would strongly suggest that anyone who is smoking "only while drinking" or "only occasionally" or "only when bumming cigs off of friends" should either quit now, or plan on becoming addicted. Those are really the only two choices.