What are the methods and skills to practice hard pen?

In calligraphy, whether it is a hard pen or a writing brush, the pen is the first. Write a simple horizontal line, no structure, only a pen. Writing two is to increase the change of length and distance on the basis of using a pen, which will involve structure. Write three, there will be a relationship between three strokes, and there will be regularity. If you can't write one, you can't write two or three. At the same time, the calligraphy pen is based on the "turning point of starting and closing the pen", starting, writing, closing, turning and folding the pen. The brushwork of hard pen calligraphy is "point" to reveal the pen tip, "horizontal" to the wrist, "vertical" to point, and "left" to turn.