First, the plot or storyline must have that conflict which would require it, whether it is a plot-driven or character-driven conflict. The drama scene should be necessary or vital to the plot so you must have a reason for writing it. Bear that reason in mind.

Then you write. This is where you'll use your roleplaying or acting skills. It helps if you are what they call 'emo'. I listen to Yiruma's Kiss the Rain, Taeyeon's If or any other song that would help me set the mood.