How to write poetry and calligraphy on A4 paper?

Calligraphy and painting shops sell pickaxe paper for calligraphy display. The grid is slightly larger, and some have patterns. It is ok to write works in the middle. If you use A4 copy paper, you can mark the middle part with a pencil first, and then erase the work after writing. It's best to draw some bamboo plums on the side.