The artist, Shae's comments are below:
"In this portrait I used Wolff carbon pencils mainly 6b but some 4 and 2b. The paper is 160 gsm made for pencil and charcoal work (I bought several brands at once..not sure which this is: Fabriano Tiziano, Strathmore, or Canson Mi-Tientes). I used blending stumps, kneaded eraser, regular eraser, paper towels. also a white pencil which I rarely use but tried this time. I don't like how shiny graphite can be so I avoided it this time though most of the time I use a combo. I don't like how this one is turning out. It doesn't look smooth."I think the portraits are looking very nice so far and Shae has a very good eye for proportions. I will try to address her main concerns above.
It is very possible to get rich darks using just graphite pencil, the trick is in the pressure used. If you press too hard, the graphite becomes shiny as you are embedding the graphite into the paper and compressing it. This also results in the artist no longer being able to build up the values darker as the paper has been flattened which prevents further graphite being able to settle into the paper. If the graphite is already shiny in your drawing, try using a tissue or chamois to gently absorb some of the graphite and blend it is more gently which will take away some of the shine.
For more even blending, try using harder grade pencils to slowly build up your values, such as H or F and gradually layering with a B or 2B in the darker areas. Using a tissue, chamois or soft cloth for blending helps to also achieve smoother transitions. A paper with less tooth will result in a portrait with smoother skin tones. A paper with more tooth (you can see more texture and bumps on the surface) will result in a rougher skin tone.
I have enhanced the reference photo and converted it to gray scale to show more clearly how the dark and light values relate to each other.
In the photo to the left I have drawn out the shadow areas or shapes in blue to better isolate the dark values from the light values. By building up these shadows on the sketch will help the lighter values to read more correctly. In areas where the lighter values need to be re-established, such as under his mouth on his left hand side of the chin, use a kneaded eraser to gently lift the carbon off of the page. When using a kneaded eraser to lighten, gently press the eraser onto the paper and pull off. Do not rub the eraser as this will just push the carbon further into the paper and damage the paper.