Well, looks like this was an adventure of discovery of boxes.

First of all, and I think this is very important. You very thoroughly yet with surprising consistent hashing crossed out and attempted to negate some boxes which you tought of as some sort of 'bad'. I think this is a very short sighted thing to do. As shown in one of the comics here, you need to accept and learn from the mistakes. The most horrid box that you may be embarrassed about is the one you need to accept and take your time analyzing what happened and what went wrong. Crossing it out means that you do not want it to exist, or that it does not show what you can actually do and an attempt to hide it and potentially not learn from it. Now it might be anything from sneezing and the line going wonky or a cat jumping on you or just simply having an awful day and it just not working out, but you still need to think about it and accept it. Even if it is such a wild and seemingly not relevant to the task at hand, you can learn to adjust something so that the next time you sit down and perform the task you are in a better position to handle outside events. If the reason however is simply that you moved incorrectly a few times in a row, than you absolutely need to try and learn how to prevent to accumulate mistakes.

Now, that was longer than I anticipated, but with that out of the way, it is actually a pretty good attempt at the exercise.

Your hashing is pretty great, nice and neat. It improved throughout the exercise and was acceptable to begin with.

Good variation on the boxes drawn, both shapes and rotations are really good. Much better than what I did.

You did ok on contouring the edges, they do not overlap perfectly, but the intention is there. In case you were not doing it this way, I found that knowing which of the lines are going to be the edges ahead of time and when drawing them going over it at the same time helped me, but my precision is not very good to begin with.

You did quite a few mistakes on the orientation of the lines extended towards the vanishing point in the beginning. Unfortunately, because of imgur not doing you any favors and the order of the pages being inconsistent, this is difficult to track, but you learned and it is good later in the exercise. Please pay attention in the future where you started and where things should go.

At the end the lines are also mostly converging so you can see you improved and you looked at all the previous attempts and kept little notes on where things went wrong. Good job.

While I do not know what size you are working with the boxes appear a little small and this makes the exercise more difficult because you have less room for error and you do not get to move and train your shoulder enough. You might have the tendency without realizing to move to elbow or even using the wrist. I discovered many times that I probably did not even use my shoulder after finishing a day of drawing. Consider doing some larger ones for comparison of difficulty.

Pretty good job overall. I would appreciate if you could critique my attempt as well.