Alright Kat, let's get to it! Congrats on your 250 Box Challenge, this was a major hurtle and I'm glad that you made it all the way through!

While at the start of your first 50 boxes you seemed a bit uncertain about how to trace back toward your marked vanishing points, over time you started to get the hang of estimating your box edges toward their given vanishing point. Whenever you go back to draw boxes like these for your warmups, I'd recommend practicing a few in the First 50 style to help drive home the idea of following back to the vanishing point.

The second set is inherently more challenging. I noticed that in some instances, like box 99, you drew your extension lines in the wrong direction. The original problem for this box seems to have been because you drew your downward-facing edges as spreading out from each other, rather than converging together toward a vanishing point, and the broken illusion may have confused you. Here's a breakdown of how this box's edges are diverging and how they'd look if you made them converge. Most of your boxes in this section are fine, I just wanted to point this one out because of the initial problem: none of its edges were aligned to a vanishing point.

As for your final 150 boxes, I could see your convergences slowly but steadily improve. You occasionally had paired convergences, like along the left side of box 185, where two sets of neighboring edges converged separately -- this is very common and will usually buff out with practice. Sometimes it helps to draw the farmost edge of the Y first, as it will have the most extreme angle in relation to its corresponding edge on the original Y, and you can trace the approximate vanishing point that those two lines meet upon and use it to orient your remaining lines. That may be a tad confusing, so I tried to illustrate it here.

Overall, your lines have been clean and confident, and you've included a great variety of box shapes, orientations, and degrees of foreshortening in your final 150. I think you've got the hang of boxes and are ready to jump into Lesson 2. Once two people have agreed with this critique, you can officially move on!