There is a term used in fighting games (and I believe in other places just as much) known as Back to Basics (or B2B). It happens when you've gotten to the point where you can comfortably play a character well, and send assaults of power offensive maneuvers, and you've gotten combos down to a reflex level -- At that point, you forget everything you ever mastered with reflex and re-learn your character from the ground up using what you've learned through your first progression. It sounds ridiculous, but it lets you learn things you couldn't if you kept going -- You learn to understand and master small details (frame counts, how your character reacts to certain blows, sidestepping -- which is extremely important in 3D fighters) so you can not only learn how to do your old combos, but also lets you progress and experiment into new ones as well.

I've decided that perhaps I should do something similar -- So I started at the very beginning, with shapes. I started to doodle at random and ask myself questions, things I've done naturally and things I take time to think on, and asked myself some stuff. For those who can't see my very poor quality, here's a list of questions and comments I wrote on the paper:

How do I retain proper height? On all four sides?
Why am I shrinking the height?
How far should the shadow go?
This doesn't look right! (pertaining to the pyramid in the lower right corner... which looks like a square with a cross on it)

I have a fairly comfortable grasp on circles, but it shows that I do not understand shapes very well, especially in a 3D environment. Other questions I have asked myself:

At what angle does it become difficult to make a pyramid -look- like a pyramid?
How does something shrink in relation to perspective?
How does a shadow work with a boxy square and a rounded square?

If anyone has a link or two to a spot on studying shapes, it would be appreciated. After all, I can learn on my own, but learning from others speeds things up.

Please, if there's anything you do want to comment, please say so.