If you can write a seven-character quatrain in a Tang poem, one ***4*7 equals 28 words for each poem, and then leave a blank signature. You can also extract the essence of some ancient prose (China's traditional culture is extensive and profound, and ancient prose is often concise) and write something suitable for your own thoughts or pursuits. The number of words should be controlled in the early 20 s and not more than 28, otherwise it will be difficult to sign.
In a word, it is best to write it on 30-grid paper, and the content is short and meaningful.