I smoke a pack a day and feel no need to confess it. I drink rarely, if I have a dinner, and see nothing wrong with drinking, unless it is a near occasion to sin (e.g. the drinker uses it as an excuse to act immorally). I use no drugs that are not prescribed because I am an addict. Drug use is a trickier question, and it should be stayed away from, for myriad reasons, but, I don’t believe that use of any drug is a mortal sin, unless it’s sinful in another manner (such as suicide/overdose, using dirty needles, stealing to get it, etc.): it’s when addiction or obsession sets in with any drug - or any other thing, food, sex, money, success, shopping - and becomes more important than religion and God, that it becomes a mortal sin, for the “alienation of affections” for lack of a better word.
It never crossed my mind to ever consider that smoking or having a few beers be a sin - Catholicism isn’t Mormonism.
Note: when I say “sin”, I mean something more serious: many things are venial sins, from unwarranted speech and gossip on up; we all commit venial sins all of the time. Smoking is most definitely a venial sin (along with all luxury goods), because any money that is spent on it could be spent on the poor, and it’s not good for the health (it’s not as harmless as the cigarette makers want you to believe, and not as bad as the government and activist groups want you to believe). Back when I was more irreligious and I was chain-smoking while debating some Mormons (as I foolishly decided to order a Book of Mormon, not knowing it came with a pair of missionaries), who found it offensive and contrary to their Word of Wisdom, I cracked a beer and I argued - using Scriptural proof-texts - that smoking was incense for the temple of the Holy Spirit. It shut them up. That’s a condemnation of the proof-text way of reading the Bible, not an endorsement of tobacco having a pleasing odor to God, if you didn’t notice, by the way.
P.S. I also demonstrated in less than one sentence how the Mormon church is apostate by its own criteria, and in another sentence, how its praxis doesn’t match with any of its official teachings.