In the past Koreans often drank as part of religious and other holidays. In many of those events drinking was part of showing respect to old people and family ancestors. This acts have its roots in the Confucianism.
Nowadays Koreans drink in everyday life too. But many of rules in the Korean drinking etiquette are those related to elders and others who are regarded superiour in the Korean social system like for example bosses are work. Local drinking rituals also suppose to show there are positive feelings going the other way too.
After work Koreans get together with their co-workers in local bars. This meeting is known as hoesik. Another occasion where the locals drink a lot are parties held close to the end of the year.
When in a group having drink it impolite to have an empty glass. It is also treated bad manners to refuse other person offering you drink. So, if you do not want to get drunk the best way is to drink slowly. It is also possible to make an excuse by saying that you have health problems.
Koreans always drink with some food. Food consumed that way is called anju. All sort of food can be regarded as anju. Two examples of such dishes are the Golbaengi salad and Pajeon pancakes. The locals usually drink in a traditional Korean bar or Minsokjujum.
Soju is the most popular Korean alcohol beverage. Some say it is partly because of its low price. It is made in the distillation of rice, wheat, barley or something else high in starch like for example potato. It contains up to 45% of alcohol.
When in a group of people drinking it is the elder person who always pours soju. It is important to say that you should hold a glass with both hands. You put the glass on the palm of your left hand and hold the glass with the right hand.
When your glass is filled turn away from the person pouring the drink and drink your soju bottoms up. After that return the glass and pour the beverage to the person who previously poured soju. Only the first glass requires the mentioned ritual. After that just point your empty glass towards the person pouring the beverage. Second and other glasses of soju do not have to be drank bottoms up.
References Why Drinking is Important in Korea http://seoulistic.com/korean-culture/drinking-culture-in-south-korea-and-why-its-important/ Korean Drinking Culture http://m.visitseoul.net/en/m/article/article.do?_method=view&m=1004004001002&p=04&menu=0004007001003&art_id=41402&searchLoca=&searchTheme=&flag=&searchType=0004007001003 Anju (food) https://en.wikipedia.org/wiki/Anju_%28food%29 Soju https://en.wikipedia.org/wiki/Soju How to Drink Soju Like the Koreans http://www.obsev.com/food/how-drink-soju-koreans.html Images Soju (photo by Graham Hills, Wikimedia Commons) https://commons.wikimedia.org/wiki/File:Soju_time!.jpg Pajeon (photo by Debbie Tingzon, Flickr) https://www.flickr.com/photos/ilove9and23/6000457229/