Depending on how much you've improved since you made these, my comments might be more or less relevant, but I'll let you be the judge of that. xD

Your superimposed lines seem to diverge quite a bit at the end, I would suggest practicing a bit more if you haven't already.

Overall your lines are straight and show a lot of confidence, which is great. They could be slightly more accurate however, in their direction and length.

Your ellipses in planes are smooth for the most part, however it seems like you've struggled with drawing ellipses in tables, as there are several places where the curves break. This can be a sign of lack of confidence or fluidity of movement.

The plotted perspective page is beautifully rendered and very well executed.

Some of the lines in the rough perspective exercise tend to curve or have the wrong lenght (sometimes stopping before or after the dots you've placed).

Your rotated boxes page seem pretty solid overall, but the back faces of the boxes seem to have been constructed not as rigorously as the front faces, and the far-end boxes just before the ones seen completely in profile could have been turned away more, to create a better transition with the last ones serving as guides. Their top faces would have been more foreshortened as a result. (right now they're almost as wide as the boxes just before them nearer to the center)

Finally, the organic perspective exercise is overall pretty good. I notice that your boxes are a little too distorted by perspective at first, but they look fine on the second page.

I give you a silver star sticker for your fine work.