Morning in Garosu-gil, afternoon in Apgujeong, dinner in Cheongdam.
Morning — brunch and shopping on Garosu-gil; the Serosu-gil back lanes are quieter.
Afternoon — a walk through Dosan Park, then Rodeo Street and K-Star Road.
Evening — dinner in Cheongdam. Book ahead.
All three sit within walking distance or a short taxi ride of each other.