Hey leo, i see you're studying a lot. i like that.
here's some critique:
your forms are very wonky. I suggest you take the constructions a lot more seriously as if u were finishing an illustration to get the most out of it. your cubes aren't working. i'll tell you how to fix it below. The drawabox rotation grid is done incorrectly. Adhere the edges more closely and pay closer attention to the video on how he constructs it.
Drawabox is a good resource, but honestly Scott Robertson's how to draw is infinitely better. Not to say you can't just supplement drawabox with how to draw.
Rules of boxes:
every set of parallel lines of a box converge to the same vanishing point.
both sides of a box converge to vanishing points ON THE SAME HORIZON LINE.
The front edge of a box should be 90 degrees or higher.
Learn a box rotation and aim for ACCURACY of the box. So yes, draw the whole grid first. and when you draw it wrong, correct it by drawing it in a grid.
practice 2p boxes first and then add 3p when u feel comfortable with the convergences of 2p.
The whole point of learning to draw boxes is to be able to eyeball convergence and to be able to visualize edges.
The organic free form exercise is good, but it's a combination of learning cylinders and boxes. You need to be able to eyeball the degree of an ellipse and what direction the minor axis of the ellipse is to feel the form of something organic.
Prioritize an understanding of ellipse and then the cylinder.
The anatomy of the ellipse is as follows:A major axis and a minor axis. Imagine a caveman spearing a cylinder cap right in the center. The path that spear takes through the center of the cylinder is the minor axis. The major axis is kinda irrelevant. You can look up a diagram.
You can't draw a cylinder without the proper knowledge of a box and ellipse. And you can't draw ellipses without knowing how to converge a box properly and without knowing how to draw it on a minor axis.
You should aim to be able to freehand all of it so you can carry it over to sketching.
quick notes for u
Here are some resources:
overall form:
https://www.youtube.com/watch?v=FF8XgTQmoPg&t=216s
https://www.youtube.com/watch?v=lRD1UfPid58^this video has an explanation about degrees of the sides of a cube at 17mins in, but the whole video is worth a watch.
Ellipse anatomy/construction:
http://scottrobertsonworkshops.com/h2dr/x7/072.html
and this
http://scottrobertsonworkshops.com/h2dr/x7/018.html
for more info on form u can purchase a gumroad on moderndayjames
And please, make more time for doodling. allow yourself at least an hour of doodling a day. doesn't matter how it feels at first, you will enjoy it in time. if all you're doing is studying you're not learning the application portion. the whole point of studying is to commit the exercises to memory so u don't have to think about it anymore. that only comes from repetition, stretching/combining exercises, and drawing from memory.