There is a key to brush calligraphy, that is, "the hand should be solid and the pen should be empty." The first time I practice calligraphy, I feel weak because I am not used to holding the pen, because the corresponding muscles have not been exercised and my ability to control strength is poor. The only way is to practice more, keep your posture and practice for a while. Practice for at least one hour every day. If you practice too little, it will have no effect.
The most labor-saving way of brush painting and calligraphy is to take the wrist as the axis, followed by the elbow as the axis, and the most difficult is to take the shoulder as the axis, so you don't have to pursue high difficulty at first, you can practice your wrist on the case first, and then practice hanging your wrist to hold the pen when you get used to it.