I learnt a variety of Tonal Value Techniques and they are Tonal, Scumble, smudge, Hatching, cross Hatching and Accent Lines.
For cross hatching I did darker shades of Lines. How I did it was bye shading. The more lines I draw over the top of each line the darker it gets. The lease line I draw the lighter it gets.
I really enjoyed Shading it so I can get better bye shading things.