Is there any special way to write and send letters?

Buy a roll of telegram newspaper, tear off 10 meter and write a 9. A letter 9 meters long.

Then roll it up and send it in a paper tube.

Another year, I sent a letter to my father's birthday. Except for the outermost envelope, all the envelopes inside were made by myself, one smaller than the other, and each one was written with a blessing. When the innermost envelope is opened, it is a self-made card (of course, the size is very small).

I like the number 9 because it is the largest number.