Wonderful, good going on completing all 250 boxes! I'll be going through them 50 by 50, see if I can find anything to give feedback on, and perhaps see some progress while at it.

Boxes 1-50

Err.. give or take box 1-50, you haven't numbered them! I'm just gonna assume you indeed drew the full 250 and just review every 8 pages instead.

For the first sets of boxes, your lines are drawn very wobbly. Be sure to keep practicing that ghosting technique from lesson 1, it's very important moving forward. Remember that speed is more important than accuracy! Accuracy will come with time, but if you make your marks too slow, you'll never learn to be both accurate and sharp.

I also see a bunch of lines where you made multiple marks on top of eachother. Just stick to a single mark, if you make errors, roll with them. That's why there's a full 250 boxes to go, plenty to fix later!

I also see you haven't done any hatching, nor did you add lineweight to your boxes. They are admittedly optional, but I still highly recommend you do it. It's a lot of practice you've been passing up on.

Lastly, your extension lines are very short. It's generally recommended to make them about twice as long as the lines of the boxes themselves, give or take.

That said and done, you are already starting out with great creativity on your box shapes, and you're drawing nice and large boxes which is only to be recommended. But much much more importantly, you have a good sense of perspective, which is what this exercise is about in the end. Your lines converge to a single point properly and consistently, very well done.

Boxes 51-100

I'm already seeing a lot less wobble in your lines, so you fixed that on the go. It's still visible in a lot of boxes, but it's much less than on the first eight pages. I still see a good bunch of re-takes and scratches in your boxes. I also see you have some issues getting the center two lines to align properly, turning it into "sets of 2" instead of four properly converging lines. This is especially noticable in boxes such as those on page 15.

Boxes 101-150

Starting to lose a bit of creativity in these boxes, a large amount of near-cubes with their VPs all at about the same distance. A lot of wobble has returned, and there's still double marks all over the place. While the initial boxes were honestly pretty good, I am not noticing much progress over the last 100 boxes or so.

Boxes 151-200

In fact, I see backwards progression. The boxes in this set feel very rushed, a lot of the straightness of the 51-100 set disappeared entirely, there's more scratching, but even the clean convergence of lines is gone now.

Boxes 201-250

I'm afraid I can't let this pass, I'm sorry :( the boxes became downright messy at this point. I'm not sure if it was impatience or not, but the quality of the first hundred boxes was much better than the last 150.

Overall

You got the theory down, but not the practice. Please be sure to check this bit of advice on the lesson page, it is really important: https://drawabox.com/lesson/250boxes/1/convergences

The red lines are how you want it. The blue lines happens sometimes, it's not always easy to get lines that close to eachother to converge. But the green lines you want to avoid at all costs, there is no reason to let a line go that far off to the side. Messups are fine but I'm afraid such boxes are relatively common in your set of 250 boxes.

If you are willing to, please go for another 50 boxes, slow and careful. Boxes like the top-right, top-middle and bottom-middle on page 43 are fine, but boxes like the top-left, bottom-left and bottom-right on page 43 should not happen after you've drawn 250 boxes with full diligence. It's fine if the lines don't land on cross on exactly the same spot, but you really, really want to make sure that all four lines at least converge.

(and go for the line-weight and hatching! Still optional, but would've helped you so much with the wobbly lines)

https://drawabox.com/lesson/250boxes/1/lineweight

In the end, you're doing this course for yourself :) the way to truly learn how to draw isn't through theory, but by really putting a large amount of time in the ghosting process, planning every line slowly and steadily before making them.