Maintain the brush
In Chinese calligraphy, how to hold the Brush is very important. We can not afford to maintain it anyhow.
As a long speech is not worth a good diagram, here is the normal maintenance of brush in Chinese calligraphy:
To write very small characters, the wrist is placed on the table. For normal size characters, in a fictitious square of 5 to 10 cm aside, we must put the other hand under the wrist.
For bigger characters, it is the arm which is placed on the edge of the table.
To make big character in cursive style, we must stand up and hold the brush with its base as shown on the diagram below.
For the biggest characters (called Bangshu) we use a big brush held like this:
For writing to the vertical, on a wall for example, the brush is held like this:
Aside from the last case, the brush must remain vertical.