The main mistake many people do is trying to keep up with some seasoned drinking professional. Just know your dose, that's all. Nobody requires to drink as much as the rest do. If you don't want to drink - then don't. Most normal people will understand.
What concerns vodka - if you drink 50-100 ml it won't do you any harm, quite the opposite, especially if you had been eating some fat food (like pork, for example). It's only when you drink a bottle or seven you're in trouble.