What was the description of flowing clouds and flowing water, the finishing touch, and the wonderful brush?

Flowing clouds and flowing water, the finishing touch, and the wonderful brush were the techniques used to describe the actions, thoughts, and emotions of the characters in novels. They often appeared in martial arts novels, fantasy novels, and other works to describe the actions, words, thoughts, and so on. They were very smooth and natural, flowing like a river without any sloppiness. At the same time, they were like a magical brush that outlined a vivid image with just a few strokes.