Here is my pencil sketch of Darth Vader Interrogating a Rebel Officer ... created with the pencil tool on Autodesk Sketchbook.
These are my process sketches,
INT. REBEL BLOCKADE RUNNER - CORRIDOR
The evil Darth Vader stands amid the broken and twisted bodies of his foes. He grabs a wounded Rebel Officer by the neck as an Imperial Officer rushes up to the Dark Lord.
IMPERIAL OFFICER
The Death Star plans are not in the main computer.
Vader squeezes the neck of the Rebel Officer, who struggles in vain.
VADER
Where are those transmissions you intercepted?
Vader lifts the Rebel off his feet by his throat.
VADER
What have you done with those plans?
REBEL OFFICER
We intercepted no transmissions. Aaah... This is a consular ship. Were on a diplomatic mission.
VADER
If this is a consular ship... were is the Ambassador?
Source: http://www.starwarsarchives.com/dt_gallery/scene-05-interrogation/