Hi all, 
Please improve your hand drawn sketches via Photoshop.
As I have demonstrated in class; Basic adjustments in the levels, contrast and curves  section, do a lot and don't take much time.
(In the top bar of Photoshop; click Image-Adjustments-Levels and/or Curves and/or Contrast)
Good luck!
For more detailed work please view this tutorial:
https://www.youtube.com/watch?v=9HR3IgftbDw