Hello, Alby.

First of all congratulations, it's a tough challenge to complete (at least it was for me). I have to tell you that i chose to review you as i saw you made some critiques for others, that's why i prioritized your submission over others. This is your reward :D. It's also an essential learning step, so keep helping the community.

Let's begin with your submission.

Your lines are confident and the overall technical aspect is good. The bad side is that you missed to extend the lines towards the vanishing points. I have seen that you asked about how to identify which face you should hatch. The answer is, you can choose which one you want, because as you are drawing boxes and not cubes, you can't exactly tell which face is nearer the viewer. Although you can use some rules of thumb to decide, for example the nearest face will be bigger than the rest. Also you can use the convergence of the two axis that forms a face to decide, usually the less convergence the nearer the face is to the viewer (this could be distorted with some boxes that has a corner as the nearest point of the figure).

Your lines are extended most of the time in the wrong direction. I assume this is because you don't know where is the viewer so it's difficult to tell where is the opposite direction. I'm going to elaborate on this so you can get a better idea.

When you begin one box, you place 4 dots. One is the seen corner, and the other 3 will form the axis that separate the 3 faces that are nearest the viewer. You have to choose one of these to hatch, you can try with the advice i previously gave you before to choose it. After placing that 4 main marks you place 3 more that complete the silhouette of the figure and lastly you place the inner corner mark and join every mark that you place letting the inner corner for the end.

After doing that you will have to extend the lines in the same direction your main axis were. From the first middle corner that's near the viewer, to the side of the other 3 points you marked on the first step.

Also you didn't explore foreshortening and you should. It's part of the reason you have trouble figuring out the exercise, because dramatic foreshortening makes clear which faces are near due to the extreme size difference of each face. Also shallow foreshortening is a goal you should be trying to reach for.

You didn't try adding lineweight to the silhouette but in your case, as it's an optional step and you have other problems to worry about, you can deal with this later (if you want). This will be one of the main points of lesson 2 so you will have to practice it sooner or later.

As final advice, please make the submission easy to critique. Yours' is filled with red lines everywhere and it makes it harder for anyone to analyze it. Try to use at least 2 different colors, one for the extended lines, and other for the box itself. This could be also useful to you because with so many lines it's normal to have trouble distinguishing which line is which. Have that in mind for your next submission.

I'm going to ask you for 30 more boxes. At least 15 should have some sort of foreshortening and try to aim for shallow foreshortening. I want you to focus on extending the lines on the right direction. Answer this critique with your revision and i will give you some more critique.

If you have doubts of the process of making the exercise you can check this video of ScyllaStew that has a lot of useful things to deal with common problems like the inner corner. And I recommend you to re-watch the video of the challenge and then re-read the challenge itself.