Marshall from a Draftsman podcast episode.

one more.

2 more.

I think you're grasping a little more than you're giving yourself credit for! These are looking really good! No need worry too much about how long you're taking on each. Take your time. Your perspective boxes and portrait lay ins are looking pretty solid, you have a good likeness with each, you paid attention to line weight, your shapes and lines are nicely simplified. Great work especially for eyeballing it. That said, I'd suggest starting to incorporate some measurement taking into your process. You can only improve your results. The division of thirds in your top cube examples are not equally divided, specifically in examples 1, 4, 9-15, 17. Often you're making the middle third too thin, or over exaggerating the foreshortening. You have a fairly even 3rds division in example 18. Try to maintain that even division even when the head is tilted into perspective. The sections will get smaller as they go away, but it's very subtle. These 3rds measurements can and should be adjusted for each individual model, but starting with an accurately divided frame will help you make those adjustments more accurately when you take a measurement from the model. Keep up the good work.

Nice work! These read clearly, and you achieved a great likeness with each! There are a few convergence issues here and there, make sure you're sending each line to the correct vanishing point. Also with the last face, your vanishing points are very close causing a warped perspective in the box, this causes distortion almost as if you were viewing the box/face through a fisheye lens. Placing your VPs further apart will yield a more subtle convergence and help keep features feeling natural and aligned properly. Hope this helps! Keep up the good work!

lol this fast makes me mad I have to redraw it

Really nice work, these are all looking great! Check the perspective of the box examples in #4, #10, #14, they're are a little off here and there, but the portraits all look like you made the correct adjustments and kept the feature lines converging to the correct vanishing points. Way to do a bunch of portraits!! Keep up the great work!