Unfinished Experiment Oil Sketch

I read somewhere that Sargent would start a painting by using charcoal to make indication marks for the face/other parts of his subject and then wipe the canvas to leave light charcoal marks and to tone the canvas. For this oil sketch I attempted to do the same thing. I think I may have put down too much charcoal. The charcoal that remained after wiping the canvas down mixed in with the oil paint block-in, which made it impossible to get accurate color.

I wasn't too concerned with getting a literal likeness... and I goofed up the color temperature in the shadows. I decided to just play around with the paint and experiment to see if I could accidentally make some oil painting discoveries.