Look at the inheritance.
Calligraphy has a strong inheritance. Generally speaking, when you see a work, you first look at the family and school it inherited from history. Those who are successful are those who are good at teaching and innovating, and have formed their own unique style. If you can't rely on it, you can't join the stream.
Look at the writing style.
It depends on whether each stroke of the work complies with the regulations. This regulation is established by convention. For example, Tang Kai script requires that the head be hidden and the tail removed, and Han Li requires silkworm heads and wild goose tails. If it is violated, it will be a failure. If there are too many failures, the work will not be successful.
Look at the calligraphy.
The structure of each stroke must be legal and reasonable, whether it is long, short, flat, square, biased, oblique, fat, thin, horizontally thin, vertically thick, or about the same thickness, etc. The overall effect of lines and chapters should also be taken into consideration.
Look at the ink method.
A good work should have "dense ink and moist characters, light and changeable ink; no dry brush when dry, no swelling of ink when wet; moderate fat and thin or both fat and thin, and full of interest in ink."
Look at the rules.
Just look at the chapter structure of calligraphy works. A good work should have appropriate handwriting size, weight, density, coherence, mutual response, consistency, and overall coordination. Some works look good individually, but the overall feeling is not good. This is the problem.
Look at the style.
Calligraphy should not only be inherited, but also have individuality and form its own unique style. Such as dignified, strong, elegant, chic, etc.