Line Quality?

So I have really been trying to push and develop various types of marks. These are a couple of the more successful drawings. I make a lot of bad drawings these days but it's always fresh and new whenever I draw. I usually don't spend more than 90 minutes a drawing.

Fig Jan 26 Feb 2

Toned paper with black and white pencil. 12x18
Charcoal 18x24
This was done on some cheap paper it was hard to push the values.
Nupastel. The most difficult medium I have ever worked with...