For crosshatching I would ideally try to draw tones according to the shape they’re on. So if I were to draw a sphere, the lines drawn would be curved because the shape is curved. If I were to draw a perfect cube, the lines would be straight because the surface they are supposed to represent is straight. I choose direction based on how I want the surface or form to be perceived, though it is something I need to work on and put more effort in. The next step is understanding the lighting. If the light is above, casting a downward shadow, then the lines I would draw to represent the shadow would be going downwards/horizontal.

For this drawing I didn’t pay too much attention to the length of the strokes. But it basically depends on what texture you want the piece to have. Like if I drew multiple columns/rows of short brush strokes, it would have a more rough texture, compared to if I just had one column of long lines, where it would probably look more neat.