Hello, Elstree:

Let's begin with the critique!

I don't see anything problematic on the lines exercises. There were some fraying on the superimposed lines, but that's common if it's present only on one end. There were pretty confident strokes, even when they were covering large distances. I wouldn't worry about accuracy because it will take some time. You are on the right path, nice work.

I think you struggle a bit with ellipses. They were less confident compared to your straight lines, but that's normal. I would try to change the speed you are using to draw them. Play around increasing and decreasing the speed you need to draw a smooth ellipse, and work from there to improve the accuracy. Remember, it doesn't matter the exercise, smoothness and confidence is always first, then you can look for accuracy.

This made your ellipses bumpy when drawn on the planes, it was because you focused on touching the sides of the plane. It's is more important that you first do smooth ellipses and then try to reach the boundaries of the planes in the ghosting phase.

Your ellipses on the funnels exercise were better because of the same reason. You were focusing less on the accuracy and that improved the smoothness and confidence.

Now, let's enter the tough topic... boxes.

The plotted and rough perspective were good. It's not expected to match the vanishing point and you will improve that kind of estimations over time. You did well by doing the complete process for each line, mark, ghost and draw. Don't forget it, it's the base from now on.

The rotated box exercise has some mistakes that are important to point out and for you to understand so if I don't explain properly, for your own sake, ask for clarification. I recommend you to re-read the exercise description too because you could have missed the details on the exercise description.

The square feeling you can see it's because of the convergence and vanishing points. Neighbour boxes should have some set of lines similar, but other sets should be different. Let's have the horizontal row as example. They are rotating along the vertical axis, so the vertical lines should have the same vanishing point and as consequence be almos parallel between them. The horizontal lines, in the other hand, should be converging towards a moving vanishing point and diverging towards the other. It is well explained on this gif

The organic perspective was great as well. You did improve a lot through this lesson, congratulations. You can move on towards the 250 box challenge. I recommend you to take a daily goal (5-10 boxes per day) to not rush and let the muscular memory to sink in. Remember to warm up before each session mixing up some exercises from this lesson you have completed