Many students have taught themselves confidently, not to mention how strange the painting style is, and they don't even know where to start. The process of painting from elementary to advanced is just like the process of reading from elementary school to university. The correct way is to have a graded, evaluated and gradual learning process. Shall we draw a sketch first? Or should we start with anthropology? Later, I found that I should practice my lines first, so classroom learning is an efficient qualitative learning method.