how do you write a cipher?

Question

not a computer program but a hand written cipher one that my family can use as code for ourselves

Answer 1

Why would you give 10 points to someone who just cut and pasted and didn't even list a source? In your hamburger question?
As to a cipher, you can get information from the link I have provided below....good luck.

Answer 2

Create a mapping of letters. You can also adjust them based on position if your family is really geeky.

Otherwise just Do something like:

A-Q
B-M
C-R
D-Z
...
Z-D


Just make sure the each letter appears once and only once on each side.