To add to pirate's answer -
A mirror cipher may be simple enough - you know, where the ciphered text would read:
:daer dluow txet derehpic eht erehw ,wonk uoy - hguone elpmis eb yam rehpic rorrim A
Or perhaps an ascii cipher, where you spell out words with letters... of course, you run the risk of someone misreading what you write, but that's up to you to make sure your message is clear.
Per Caesar ciphers, I always thought it might be a clever clue to give the name of a Caesar alongside the encrypted text - so that the nth number to shift in the cipher would be given by the nth Caesar.