The key to drawing a comic opened door is to observe real doors for reference. Decide on the style - whether it's cartoony or more realistic. Start with a rough draft, refine the lines, and don't forget to add some background to enhance the scene.
First, start with a basic outline of the door shape. Pay attention to the proportions and perspective. Then, add details like the handle and hinges. Shade and color it to make it look realistic.
To draw a comic opened door, you need to understand the structure of a door. Sketch the frame, then focus on the open part, showing the interior or whatever is behind it. Use bold lines for emphasis and light shading for depth.