I'm sure we have all heard the tales of how to aggravate some kind of "ghost" in a mirror. I tried every one I could find, and nothing. However, this is because it isn't really a ghost in the mirror, it's you. Not a different version of you, in reality, we exist in as many places as there are mirrors at once. But there is a real way to do something interesting with a mirror. The other side of the mirror contains a world where all your wildest desires are yours.
You just have to do one thing. Tell your mirror these words: "You are everything I have ever been and I am willing to accommodate all credit I ever had into one entity", and then shatter the mirror quickly. If not done quickly enough, a demonic moan will be heard as a giant hand grabs you and smashes your head into the mirror. If done correctly, your reflection will climb out of the mirror, and let you enter his world, but on one condition of course; the only way you can leave is if another mirror you have decides to try this process.
If not, you are stuck there forever. Oh, by the way, you wouldn't want to know what happens if the mirror world you're in gets broken. Let's just say that brings bad luck.