1 - Superimposed Lines:

I see a good job here, you have a straight line with relatively low fraying. My advice here could be to practice more this kind of exercise by enlarging every next set of superimposed lines consecutively until you reach the length of the paper. You could vary the form and length of the curves too, in order to get your arm accustomed to those kind of traces. Your lines have are a bit wobbly, but that will get better the more you use this exercise as a warm-up.

2 - Ghosted Lines:

The principal problem here is your lack of confidence in your traces. This tells to me that you aren't ghosting enough or you are doing it in a ineffective way, like moving your arm from the start point to the end point and vice-versa equally, like a pendulum, that messes up your muscle memory. What you need to do here is to place two visible points, a start-point and an end-point, then place your hand holding your pencil over the start-point and then confidently do an "imaginary" trace to the end-point, hovering your pencil all the way from start to end, as you will do with a real line, with the only difference of being touching the paper with the pencil. Maybe you need to review the material on ghosted lines in the main site again in order to get the gist of it.

You could vary the size and the angle of these lines a bit too, by rotating the paper, so you draw the same line in different lengths and angles. Don't be afraid of overlap them too, so you can practice very long lines, no matter they are intercepting each other.

3 - Ghosted Planes

Good job here too, there is little to say about your lines, because the errors here are the same from the other two exercises. You need to practice more your ghosting in order to get more straight and confident lines. Again you could vary a bit more those planes, so you can practice a more diverse kind of quadrilaterals, by drawing their corners with different angles and lengths of lines.

4 - Ellipses:

The main problem here is your wobbly line when you draw your ellipses. When you lack the muscle memory to draw ellipses, your brain tries to do some "auto-correct" the line, making you do these weird turns when you draw your curves. Something that could help here is to have an example of a drawn ellipse (like the ones in the main site) before you ghost the from of said ellipse, so you are mindful of the form of an ellipse and his minor axis. Try to ghost them until your shoulder seems to "get" the curvy form of the ellipse (maybe 5 times), then draw the line, and don't do more than 3 overlapping loops (2 is the ideal). The ghosting will help you to combat that "rectangular" look of your ellipses, made by the "plane sides" by narrow turns.

I don't recommend to fit every blank space with ellipses, that makes you to deform every new ellipse drawn to fill the space leaved by another drawn earlier. Its highly difficult (and by the way, not the objective of this exercise) to calculate the perfect number of ellipses for each segment (unless you use a rule and a calculator, and again, its not the objective), so just be committed to make your ellipses look as curvy and natural as possible, it doesn't matter that you leave a bit of a black space here and there.

5 - Funnels

You almost got this one, but the problems here are the same of the ellipses exercise. Again, you aren't confidently drawing those ellipses, so your mind tries to micro-manage your arm, assaulting your muscle memory and messing up your curves. You need to be mindful of the minor axis of every ellipse you draw, so they align with the "Y Axis" of the Funnel. I recommend to review the theory of funnels in the main site again, just the video.

6 - Ellipses in Planes.

As you can guess, the same problems in the planes and ellipses exercise applies here too. On the other side, your ellipses here starting to look way better than in the other two exercises. This is one I seriously recommend to choose for warm-ups as much as you can, because you can practice ellipses, ghosted lines and planes in 15 minutes before draw. Try to do a better use of the paper here too. Draw a diverse group of quadrilaterals, not only some small and other really big, that will force to yo draw a variety of ellipses: big, small, large, short, etc...

7 - Plotted Perspective.

Good job here. This is a very straightforward exercises, so there is little to say. My recommendation here is just to vary the size and form of your boxes a bit, maybe the position too. The idea is to be familiar with a diverse kind of boxes.

8 - Rough Perspective.

Maybe you need to review the theory of vanishing points (the so-called VPs) and perspective here. I can see that you fail to construct your boxes in one-point perspective because the lines of the sides of your boxes aren't converging to the VP (even knowing that the very probably they wouldn't, because the inherent difficulty of this exercise). Instead, they are diverging. In some cases, each one to their own way, showing that the box is badly constructed in a way that reflects that you need to review the theory of perspective and boxes exhaustively.

In other instances, you aren't projecting your red lines using the lines from the sides of your boxes but weirdly the vertices. I guess you noticed that, using the sides of your boxes to project it to the VP (as it should be) you will never reach it, because they are erroneously constructed, and the lines will be projecting to the horizon, again, on their own ways. What you done here is plainly shying away from your mistakes, careful with that!!. Draw a Box is about trial, error and advance. By shying away from your mistakes like you done here, you not only fail completely this, but the entire point of any lesson.

Again, my best recommendation here is to thoroughly re-study the whole perspective and boxes theory, and redo this exercise completely.

9 - Rotated Boxes:

Taking for granted the inherent difficulty of this exercise, this was a good try!. You have here a classic problem that many beginners have, and that is, that you are making your boxes smaller instead of rotating them, here is an example of what is happening in your draw: https://d15v304a6xpq4b.cloudfront.net/lesson_images/d73eea49.jpg Remember that, if a boxes is being rotated, then 2 of their VPs, the ones that are "touching the horizon", moves along the line of the horizon, conserving the distance between them. Other ways, the box will be deformed. Go here to see this point on an animated example: https://drawabox.com/lesson/1/16/rotation So ideally, when you rotate your boxes properly, should look like this: 

https://d15v304a6xpq4b.cloudfront.net/lesson_images/4018ab0f.jpg

Don't make your boxes too close each other, as you draw every box related every ones to each other, if you draw a bad box, this one will deform the ones adjacent to it, and so the others to even others. For example, in the first "mid" level of this sphere of boxes, as you badly rotate the first row, and the adjacent boxes to the central one get smaller instead of rotated, as you draw a box in the upper or lower level so close to this badly drawn box, you will feel "subconsciously obliged" to correspond to this older box with the form of the new box you are drawing right now in another level, hence, deforming it because his "closer parent" is deformed. You can combat this problem by distancing the boxes a bit, like in this example: https://d15v304a6xpq4b.cloudfront.net/lesson_images/5f4fef59.jpg See how there is a space of like, relatively speaking, a half centimetre. So its more difficult to accidentally deform a new box by subconsciously (and actually, physically) trying to draw a new box familiar to an adjacently older box.

You have a problem of disorder here too, caused by badly rotated and positioned boxes, like in this example: https://d15v304a6xpq4b.cloudfront.net/lesson_images/9a16c189.jpg This problem, and your rotation problems will get much better when you finish with the 250 box challenge, but for practice, you could do some warm-ups by drawing only one quadrant of the sphere, so you will be getting expertise bit by bit.

10 - Organic Perspective:

The main problem here is that, in many instances, you draw the same box in many places, just a bit smaller or a bit bigger. This could reflect that you are maybe getting a bit tired of the Draw a Box exercises. Maybe, if you were grinding a bunch of exercises the same day you made this one, you were needing a rest, but you didn't, so you made this one "as it comes". On the other side, if you done this unconsciously (or even on purpose), then you are missing the point a bit. The whole idea is to draw a diverse group of boxes with different forms and sizes, but not randomly. The gist is in draw the smallest box you can draw in the starting point on the curve you drew and the biggest one at the end, so you can get this feeling of a "train" of boxes so long that seems to be coming from far away. Fox example, check this: https://d15v304a6xpq4b.cloudfront.net/lesson_images/598a86fb.jpg You can see variations on the position and sizes of boxes as every one is bigger than the last ones.

The other problems are inherited from a lack of understanding on box construction and perspective, and lines done without confidence. So, I recommend you do more warm-ups on your ghosted lines and one segment of these organic boxes in order to master it little by little.

That's all, hope it helps!! :)

A decent attempt. Well done for making it this far!

Overlapping Lines

Very wobbly. Make sure you're using your entire arm and that you keep a consistant speed with each stroke. This should also reduce the large amount of fraying that I am able to see.

Ghosted Lines

All right. There appears to be a slight wobble, as well as a lip at the end of each line. Maintain a consistant speed using your pen. Don't get shaky!

Ghosted Ellipses

Pretty standard attempt. Most of the critique of your ghosted lines applies here, but you're slowly getting better. Don't give up!

Table of Ellipses

Very wobbly and not all that tight, but that's to be expected at this stage. Minor axis seems under consistant control however, so well done for that.

Funnels

A very similar minor axis on each ellipse inside the funnel. This isn't the behaviour that is expected from this exercise. Each ellipse should have a slightly larger minor axis than the one before it.

Ellipses in Planes

Pretty good. You seem to be getting the hang of this, but as you continue to improve your art, I'd like to see you having more control over those ellipses. Your comprehension otherwise seems amicable.

Plotted Perspective

Excellent. Homework is well laid out and you used the correct method. I would have liked to have seen you attempt to plot boxes with more extreme dimensions.

Rough Perspective

Very wobbly. I know this exercise can seem intimidating, but you've just got to keep in mind that each exercise builds on the one before it. You need to take the confidence of the overlapping lines, as well as the accuracy of the ghosted lines and put them together to create boxes in perspective, watching for where they will converge as to line up with the vanishing point. It seems like you found this one very difficult, but you could make it much better by ensuring that lines converge in the same direction. By which I mean they should face towards each other, not away. Hopefully that makes sense.

Rotated Boxes

ALMOST! Your interior boxes seem to have the right idea, but you seemed to have panicked towards the end and picked random vanishing points to finish off with. Remember that these points change gradually and blend into each other. This is a hard exercise and it will take a while to understand fully.

Natural Perspective

A decent attempt, but you only submitted one page! Since I'm a nice critic, I'm gonna let you off since you appear to have understood the concepts well, improving on your boxes from the rough perspective exercise. Those notes must've really helped out!