Hi Puffer! I'll be reviewing your work. It's a long one, so be prepared:

The first issue I see is that there are a lot of boxes in two point perspective, even some in one point perspective; 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, that's why there's all this emphasis on the convergence of lines, foreshortening, the back corner, etc. We'll come back to this.

On some of your boxes, the lines don't seem to converge, and even diverge in some cases.That's a problem: 3 point-perspective boxes will always have their lines converging at some point, even if it is subtle. Here's an example of what you shouldn't do.

And here's how it should be. On that note, I'll take a phrase verbatim from my own challenge:

Remember that when you are adding lines to a set of parallels, you need to take into account the relationships with the whole set of parallels instead of just one line. When you have to guess how a line is extended into its vanishing point, its not enough to just compare it with the first line you draw of that set, you have to take the others into account to guess more accurately.

Take your time with these concepts, they can be confusing.

This relates to a big issue I'm seeing: you're extending your correction lines the wrong way quite often, like in boxes 176, 204 and 222. The thing is that your correction lines should always move away from the viewer. See this example.

Take box 222, for example. There are two vanishing points more or less well established, but the third one (when your correction lines come towards the right, that is, closer to the viewer) has two lines diverging, thus the box ends up all confusing to look at. And even with those two points diverging, if you ignore the correction lines you can quickly make out the box and see where the mistakes are, which is the whole point of the lines. So, make sure that your correction lines always move away from the viewer, from the center of the Y outwards. Like so.

In the page of box 231, you can see that you did a lot better, that's because they are all in three point perspective, and the lines are converging, even if they're not perfect.

The rotation of your boxes is pretty diverse, so that's great. One issue though is that you're going for boxes with quickly converging lines, with a lot of foreshortening. While that's not bad, you should try to do some that are less extreme in it's convergence. It should help you to avoid some of the heavy distortion that you got.

Your lines are quite wobbly at times, but as I can see, you realized that you weren't working with your shoulder, and that aspect got better, but still, watch out for when you apply lineweight, and don't forget to ghost your lines. Be subtle with the lineweight. One line over is enough.

Some other advices: when making the extended lines, hatching the plane that faces the viewer can help you, as it leads to less visual confusion (you'll have in mind where your lines have to get away from). Also, in relation to the colors you're using for the extended lines, try to be as consistent as you can. You could use the same color for the same set of lines, and then a different one for other set of lines in the same box. That way it will be way less confusing that what you are doing now, which is to use different colors for different boxes.

Finally, you can look this up when you're doing more boxes, it is useful to make better back corners and get your convergences right.

So. As you can see there are quite a lot of issues. I will not make you do the whole challenge again, because you did a fair amount of work, but between the one/two-point boxes and the constant divergence of lines, you will have to do some more work. There at least 43 boxes with one/two point perspective instead of three (and I may have missed a couple) and considering the other issues... let's make it 60.

60 more boxes. I know it is a lot, but I think that with less you wouldn't have the time to mess up and correct your mistakes. But let's make them count. Go back to the 250 Box Challenge page, see the video and read the page again, and when you are working at it, if you have doubts, look at it again, keep it open. Check this review again too. Ask on Discord, the community is great and always willing to help.

Also, I hope you don't lose motivation. This challenge is hard and it is meant to be that way. If it helps, my challenge took me two months, drawing five boxes per day, every other day, with some misses too. And you can go see my boxes too and you'll see that a lot of them were really messed up.

So that's it, good luck! Take your time, think about the process. I wouldn't suggest that you do more than 5/6 boxes per day. When you're ready, post the homework here to see it. If you have any questions, I'll be happy to answer them.