Putting the tattoo on the mirror is a good idea,but it mtght be a good idea to take it a little further and put the image on a few other things. Like computer screen saver or on the dashboard of your car. The thing will be on your body for the rest of your life and you will be looking at it all whenever you look at your limb. I've been doing this with the Image I've thinking about for well over three months. Haven't got the tat yet though. There is no formula to decide what to get though, nor should there be.