I professionalized my sketching abilities at Delft University. Some examples are shown below just to give a quick impression of my style.

Hand sketch of a car interior using markers and pastels.

Spaceship doodle. White pencil, black marker, white and black pastels on blue paper.

Design proposal of a mitre saw for a student project. Hand sketch using markers and pastels.

Sketch of modern transportation, created with Corel Painter.

Quick render of the Shark Stapler made with Autodesk Maya.