by clicking :)

pay attention and take your time. The timer makes it appear that speed is extremely important. The issue is that if you don't take the extra fractions of a second to try and remember what you saw and where it was you waste more time clicking wrong pairs (I also think you loose points for bad combos). Since DJY put up the challenge I decided to take the time and do it as right as I could. I also do it methodically left/right and up/down.