If you want to be able to draw from imagination your subconcious needs to be able to imagine the outlines of 3d shapes automatically.
This gets easier as your brain gets exposed to more an more boxes/cylinders/egg shapes etc. We can only conciously focus on like one or two things at once, you need to train your subconcious to take care of the fundamental shapes so your attention can be on the drawing as a whole.
Best case you should be easily able to correctly draw only the outlines of a box without drawing any of the inside on top/behind the box.
>>7954261 >digital instead of physical >no line extension to check convergence >small-dick boxes when you should only be doing 5 large box per page Disingenuous fucks, just go back to copying porn.