7:56 PM, Sunday June 7th 2020
Hi, Molly. Congrats for going through this challenge. It's not an easy one, but I hope you understand the benefits of doing it.
After going through your work, one think I noticed is that you seem to be using a pen that is much thicker than the recommended ones. Now, I understand the rules don't apply so strictly for non-patrons, but I still recommend you used something in the range of 0.4-0.6mm, as using a too thick pen might hide possible mistakes (like lack of smoothness). It's always good to easily identify your own mistakes in order to improve faster.
While your line work seems overall good, you still struggle a bit with some aspects, mainly on how to extend your lines. This step is very important, because it's what helps you check if your boxes are correct in terms of perspective.
Because it's virtually impossible for me to analyze each of your boxes, I'm going to dissect one of them, hoping that explaining what went wrong might help you improve your further work.
Take a look at your box No. 242
You extended the blue lines in the wrong direction. Actually, the red lines that you crossed as incorrect are correct, but you wrongly assumed that because your box is converging up you should extend the lines up as well. Sometimes, students have the idea that the lines should be extended in the direction to where the box converges. This is wrong because if the box is converging in the wrong direction, you end up extending the lines also in the wrong direction, which is what happened here.
Reread this section to better understand what I mean.
Also, pay attention to this part of the 250 boxes video and notice how Uncomfortable says (around minute 6:30) that each line of the initial Y point to a vanishing point. So, after you finish a box, that direction to which the lines of the initial Y point is where you should extend your lines to.
Understanding this well is what will allow you to easily point out your mistakes and focus on avoiding them on the next boxes.
You have plenty of boxes where you extended some of the lines in the wrong direction.
Also, remember that the planes that are facing the viewer are the ones that touch the lines of the initial Y.
If you get these concepts right, you will definitely draw better boxes.
If you have any doubts, don't be afraid to ask.
Next Steps:
I ask you do draw 2 more pages of boxes. Five boxes in each page.
Draw them a bit larger then what you did in these 250 ones and use the method described in the video. That is, draw the initial Y that will determine the front planes of your box. Also, don't draw weirdly shaped boxes. In reality, most boxes have rectangular sides. Some are wider and others are thiner, but they are all simple boxes. Don't venture into trying to draw pyramid shaped boxes or similar things before you are able to decently draw simple ones.