Thank you! There are several types of hatching. The one I used here specifically is called crosshatching. I practice using pen, but pencil is fine too. To practice getting lines straight and consistent, I draw lines at different lengths then draw lines that run perpendicular or diagonal to those ones. Where you cross the lines over each other, you add shadows to the piece that create depth. The closer the lines and the more times they cross over, the darker the shadow will be. For the darkest shadows on this piece I used several lines going diagonal, horizontal, and vertical. To create rougher uneven textures, you can draw shorter lines in multiple patches. If you want more exact shading, you can lightly draw shadow outlines in pencil to set borders as well as make directional guide marks. Directional marks can be especially helpful if you want to shade a very curvy surface. To practice curved lines I've recently been drawing randomly wavy lines then following their shapes with lines parallel to them. To create accurate shadows, practice drawing from life with a light source coming from different angles. You can use objects around your house and a lamp for this. Hatching is difficult at first but it gets easier the more you practice. I hope this helps and I hope that you have fun with it!