Hi and well done on completing the 250 box challenge!

Overall I think you improved a lot from where you began so well done with that. I can also see that you made a concious effort to work on the areas that you were struggling with. Here are a few things that might help which I've listed in order of importance:

  1. Distortion. Something I noticed happening more and more as you progressed was that your boxes were becoming more distorted. This is because your angles in the "Y" that you plot at the start are not all greater than 90 degrees. In 3 point perspective they MUST all be greater than 90 degrees. When following the initial Y on the Y method, the length of the lines of the Y can have any proportion, the right line can be super long and the other ones be super short etc. And same with the angles, the combination of angles between the lines of the Y are limitless, AS LONG AS the angles are always over 90 degrees.

2.Lineweight

Just like in lesson 1, lineweight should be added to the contour of the boxes, and with a superimposed line. It really helps to ground the object and to visualise the orientation of the box more easily.

When doing this superimposed line, it should be done ghosting and drawing it confidently.

3.Inner corner - I've just copied this straight from the recommended feedback on this point which I found really helpful myself:

"It's pretty normal to have the inner corners come out pretty off, as they are affected by the accumulation of previously done mistakes.

A way to improve them is to start thinking about the relationships between lines instead of just thinking about the lines in pairs. When drawing the lines of the boxes, the student should keep in mind all the other lines in the set, comparing their angles and making a guess based on them. This diagram explain this more clearly:

https://i.imgur.com/8PqQLE0.png

The diagram can be pretty hard to understand at first, so if you don't understand it, don't get frustrated, keep reading it from time to time while practicing regularly, and it will click eventually.

A thing I've found that helped me inmediately to improve the inner corner while I was doing the challenge is to change the order I drew boxes in. By drawing the inner corner before the last line of the box, I found it easier to use the previously mentioned info of thinking about the relationship between lines, and made it easier for me to get the convergences right. Here's the order I'm talking about:

https://imgur.com/FGdtVwm

This takes into advantage something explained in the rotated boxes exercise too (taking advantage of lines that are very close), so give a look at the page if you want to know more about it."

The last couple of points I'm only mentioning here because it is present in earlier sketches you did but I definitely noticed an improvement towards the tail end so don't worry about it too much if you are are already aware of it

4.Extending lines in the wrong direction.

When applying the line extension method, lines have to be extended away from the viewer.

A way to make sure you do this correctly 100% of the times, is to always extend the lines away from the center dot of the Y, as shown here:

https://imgur.com/iNpIubA

But like I said, it looks like you picked up on this anyway since I couldn't see any more after box 62 so well done!

5.Divergences and parallel lines.

A box in 3 point perspective will ALWAYS have their lines converge. They can never diverge, or be parallel.

It is possible for them to converge very slightly, but they have to converge, even if it's really hard to notice it the convergence has to be there.

https://imgur.com/mWLlnYl

Again, it looks to me like you became aware of this as well and improved as you progressed so good job.

6.Similar orientations with boxes.

Sometimes students will tend to draw constantly the same box, or same boxes over and over. When following the initial Y on the Y method, the length of the lines of the Y can have any proportion, the right line can be super long and the other ones be super short etc. And same with the angles, the combination of angles between the lines of the Y are limitless, as long as the angles are always over 90 degrees.

Here's a diagram that shows different orientations of boxes, so check it out to get some ideas. Keep in mind that in the box challenge you should always draw from imagination, not from reference, so don't use them to copy.

https://imgur.com/Kqg6uMX

Again, well done and keep it up! I think you should move onto the next lesson but I'd also recommend that you make a habit of drawing a few boxes each day to work on the above points until you've really mastered them.