I have pen and paper ready for when I go to log in. I'll start inner space write down a code. Start the wow's loading grab another code. Wow's all loaded grab another code.
So in the same about of time I would be waiting for wow to load I have 3 codes written down and by the time I get to loading the third wow codes reset and I'm good for the 4th and final code needed.

I have tried writting down several codes ( inorder or it doesn't work) but it seems they are only good for a certain amount of time. If that time passes you can't use them.
But as a just incase. While playing I'll write down codes for emergancy dc's. Usually about every hour or so.