Personal experience: no, learning to sketch well depends on basic exercises, and drawing a good sketch head depends on understanding and grasping the theory of human skeletal muscle.

I used to think sketching was troublesome. It's good to read and follow other people's lines, but I can't sketch myself. Later, it was found that the mistake was too great, and the feeling of sketching depended on training. If you insist on drawing five sketches and one hundred sketches every day, you will soon see your progress. Don't talk too much. How did you do it? You can draw and practice at any time. A simple sketch can be done in one minute and ten seconds, mainly depending on your sense of touch. You will see progress in every painting you draw. It's really scary to look at the painting ten days ago. You can decide the amount of painting every day according to your own situation. The important thing is to persevere. It is best to sketch, just look at the pictures in the book and master the skeletal muscle theory. Dictation is also an important learning process.