Hi Bizarremeat.

Your linework is beautiful. It's confident and accurate, and you are capable of executing straight lines and curves very well. That being said, I feel like you could play around more with line weight.

Your weakest point is perspective. It looked like you were getting confused during the rotated boxes exercise. It looks like part of the confusing was coming from mixing up the face with the interior of the boxes. Something that might help is keeping in mind that the boxes along the axis are all in 2 point perspective. The ones along the horizontal axis will all have straight vertical lines, but the horizontal lines will converge. Another thing to keep in mind is that the vanishing points will shift from box to box. Ill link a diagram to show what I mean. The boxes in the quadrants follow 3 point perspective. It looked like you had the most trouble with the diagonal boxes on the outer edges. for these, you have to base the perspective and angle for them on the surrounding boxes.

general rules: the farther a point is from the horizon or axis, the steeper the angle will be.

If you have any questions feel free to hit me up in the discord

https://imgur.com/gallery/VdK5BvA