In the above picture notice how the direction of the lines are being drawn; hill and valley. When working up a hill shape draw in the direction, in the valley your direction of line is in the curve direction. Remember to treat the shapes you are drawing, shading and creating in a similar direction. Crosshatching lines will come later; learn the value scales in every graphite range pencil first before adding other techniques.
Also remember light or highlighted areas will come forward in space and dark values will sink in space. This is a principle just like gravity, the way God designed it and it can’t be changed. B graphite pencils are cool, softer and will go back in space as H graphite pencils are warmer in tones and will come forward in space as well are harder in texture. Use that fact to help set apart objects in your drawings.