Pass phrases are also good (Keep out!) or mixing numbers/symbols for letters (K33p 0ut!).Not a very safe thing to do. What happens when somebody finds it? Or you lose it? Or both?
Obscure as those may be, they can still be guessed. And you can be tricked into giving them up.
The only really secure passwords? Unintelligible gibberish. Those can't be guessed OR given up.