@Kikindaface: Thanks, but I´m not really sure what you mean. Could be a different definition of termology, but as I understand it, you´re suggesting to do more line drawing without value to give volume to a sketch. That´s actually something I can´t do, because form (volume) only exists because of value. Lines do not exist in reality, they are just a tool to draw shapes. I can of course hint at volume with lines by using line weight, cross-contour lines and overlap, but if you draw a sphere without value it´s just a circle. If you meant that, I find it a bit of an odd advice.
If you meant to focus on more perspective, foreshortening, more action oriented use of 3D space, I completely agree with you, that´s something my sketches could definitely need. But that also can show only true form with values, which is something I´m currently working on
Quick photo study for rim light studying