I would abstain from doing this, as smoking may easily bring you to being dependent. Also smoking is harmful, and I personally thinks it's a very resource wasting habit. I mean, tobacco must be cultivated and I am sure there are big fields with underpaid slave workers for big tobacco companies. What if we had Aloe Vera or other herbal (or food) cultivation fields instead ?
Around 15+ years go I quit smoking. Best choice ever, I feel much healthier and I am not poisoning myself anymore.
Alcohol is again harmful on a lesser degree. Maybe you can manage to have to have a light beer from time to time. Regarding me, I did that, but since a few years I am not even attracted by any alcoholic drink, I feel no interest anymore. Sounds a bit stupid and I don't need to feel "relaxed", I just am.