Spaced reposition and forced recall are the most effective ways to study. Spaced reputations means that you increase the amount of time between study sessions for material that you have shown to yourself to know well.
Making yourself recall from pure memory the knowledge will really test if you know it or not, and is much more effective than just trying to reread the textbook multiple times.
Alcohol is fun, but please have a friend you trust with you to watch your drinks and watch out for shady people.