/ic/ - Artwork/Critique

Toriyama san answered this already.
He told his students to learn to draw in perspective correctly, and do it enough that it becomes intuitive so they can freehand it.

How many of you can even draw the ones on the right? A box is the simplest way of depicting form in space - it is literally made of XYZ coordinates, even a child can draw a box perfectly in space with a few hours of teaching. It is the perfect foundational form for drawing anything structural with the illusion of depth in linear perspective.

Stop coping and start studying.