Read numerous examples of contemporary drama scripts that have a similar style of writing and production as the story you have in mind for your own script. While reading, note the author's storytelling techniques in regard to plot and characterization. Critically examine the story structure to see the ways in which events in the drama are arranged and how the events build on one another. Pay especially close attention to the writing style of the dialogue, as this will be your primary means for character development.
Read examples of classic dramas, such as the ancient Greek tragedies and Shakespearean plays. Since the characters, settings and writing styles in classic dramas are far different from contemporary examples, it is easier to read the texts from an objective, critical perspective. This helps you clearly see the emotional pacing beneath the story as well as the methods of characterization. These same writing techniques in classic literature can be applied to modern settings to help you write an effective contemporary drama script.
Write character profiles to develop the characters in your drama. This writing exercise will help you plan dynamic, interesting characters to drive the plot of your script. Each diagram should include basic details such as the character's name and physical appearance, as well as more complex details such as emotional traits. Profiling also gives you the chance to plan the basic relationships of your characters.
Create a plot outline for your drama script. The outline should consist of brief descriptions of the major events that drive the plot. Divide the outline into scenes to help you organize the story line. Include notes about which characters will be involved in each scene. When you write your script, periodically refer to the outline to stay focused.
Use your preliminary reading and writing activities to write a developed first draft of your drama script. While the outline and character profiles will help you keep the story true to your original conception, also allow yourself the freedom to add additional scenes and/or modify the plot as you go. This will make you develop an engaging story, because you will be able to incorporate new ideas that are inspired by the writing as you go.