Hey aeshnabx!

Thank you so much for the thoughtful review! I want to describe my thought process, not to justify my mistakes but rather to dissect what lead me to my decisions and what I can do to improve over it.

...and you seem to be aware of it, since you didn't complete the correction lines for those. They look great, but the 250 box challenge tackles three point perspective specifically...

I must've forgotten this bit of information at some point! I was indeed aware of the 1/2 point perspective boxes I drew, I even insisted in doing them in order to "practice all of the theory". In retrospect it makes sense that the challenge requires 3 point perspective only.

On some of your boxes, the lines don't seem to converge, and even diverge in some cases...

True! This was a big issue, specially at the very beginning. The way I was drawing then is more or less like so:

1 - Draw 1 X,Y and Z lines;

2 - Attack each side once.

I believe that at some point I even added a side note with something along the lines of "paying more attention to the Z axis". It now makes sense to me because it was the last set of lines I was focusing on, thus the one that ended up more distorted/poor drawn.

This relates to a big issue I'm seeing: you're extending your correction lines the wrong way quite often,

I sure had a hard time when trying to correct the boxes at some points. Partially because I didn't quite grasped the "move away from the viewer" concept and partially due to the last issue consequence: the distortion of the "Z" axis. I believe that the culmination of this two combined resulted in some misleading corrections. You can even see that at several points I have correction lines pointing to both sides.

One issue though is that you're going for boxes with quickly converging lines, with a lot of foreshortening.

I tried to vary the rotation as much as I could! Partially because I wasn't happy with my organic perspective exercise result... another factor that may have influenced it is that when the "inspiration" to draw a different angles was missing, I simply looked for an object nearby and put it in a box. In regarding to the extreme distorted boxes, they weren't intentional! I certainly did not meant to draw extreme angles this much, but I ended up with a lot of foreshortening regardless. I think that my lack of experience with this subject may have influenced it. At times I would imagine a box in my head (a simple one), and when drawing it on paper it would have been extremely distorted if compared to the original. "Lack of control"I would say, probably one the things I can fix if I practice more.

Your lines are quite wobbly at times...

I realized after a while that I was touching the table with my elbow. Funny is that it grew on me throughout the challenge; I didn't do it at the beginning, but rather in the middle to the end until I corrected myself. About the line weight, at times I tried to "solve" some wobbliness by thickening the lines, not worth!

Some other advices...

I didn't think of this "correction scheme" before! It makes way more sense, I'll make sure to apply it.

Lastly I would like to link a video that I've found that helped me quite a lot:

https://www.youtube.com/watch?v=YEYQe_81M4U

The video above is about line weight, but the way that he draws boxes cleared my vision. He doesn't start by drawing the X, Y and Z axis as I was doing, instead he straightly does 2 to 3 lines to a specific axis while managing their length. Maybe focusing at one plane at a time before setting all of the others did the "click" to me.

Also, I hope you don't lose motivation..

You can surely know that with such an informative critique you just motivated me more! Now that I know why some pages looked better that others, I can make a small list with the main points and always review it before practicing my boxes. I'll happily draw another 60 boxes and whatever quantity more is needed until I'm confident with it. I was planning to use this challenge dynamic to warm up before drawing anyway, I find it kind of fun for some reason.

Once I'm done with the 60 extra boxes I'll make sure to reply here. Until there, take care.