There are many things that can be engraved on the pen holder. Here are some possible choices:
1. Poetry: You can choose some poems related to the pen, such as "Reading thousands of books, "The writing is like a spirit", "After reading it on paper, I feel it is shallow, and I know that I have to do it carefully", etc.
2. Famous aphorisms: You can choose some famous quotes or your own mottos, such as "I am born with talents that will be useful, and I will come back after all the money I have spent", "There are close friends in the sea, and there are neighbors in the world", etc.
3. Scenic spots: You can choose some words or phrases related to your hometown or scenic spots, such as "Huangshan", "West Lake", "Guilin Landscape", etc.
4. Book titles: You can choose some book titles that you like or find useful, such as "A Dream of Red Mansions", "Water Margin", "Romance of the Three Kingdoms", etc.
5. Name or font size: You can choose to engrave your name or font size, which is not only commemorative but also decorative.
It should be noted that the content of the engraving should match the material and style of the pen holder, and the font, size, position and other factors of the engraving should be taken into consideration. In addition, the engraving process also requires care and patience to avoid damaging the surface of the pen holder.