3:31 PM, Thursday January 21st 2021
Regardless of how bad your initial forms look, don't draw over them. Accept them, and consider them as real 3d masses. Like you said drawing over them will only make them look worse.
These lessons exercises objective is not to make appealing drawings, but to teach you how to think 3d on the page, so don't worry if the results look bad. So ghost, draw confidently and accept the result.
For the contours, focus only on the intersections between forms. Doing a lot of contours in the middle of forms is risky, because as long as you rush one a bit it will flatten the form very easily, and they aren't that strong anyways. Doing a good contour on one intersection will be much stronger than a few good ones on the middle of a form.
I've also noticed you've been drawing a lot of detail on the drawings. As you're struggling with the basic forms, I recommend to skip detail and texture altogether for a while until you're confident with the construction.