Appearance is important in Korea as in many other Asian countries and it is important that you look your smartest at all times – both for formal and informal gatherings.
The conservative convention of dark suit, shirt and tie are still very much the norm in Korea with smart business suits or dresses being favoured by women. (Trousers tend not to be worn by women in business situations but are acceptable in informal, social settings.)
Good quality accessories are very much valued – so long as they are not overly ostentatious.
The winters are very cold in Korea, so be sure to take suitable coats, scarves, gloves and hats. Summers are hot and therefore lightweight suits are needed.