Watch this video. An old trick I also liked to use like many others.

You look down, hit the body a few times then kick up.

Or another classic I show first to explain the concept of neurological anchors in combat that I'm sure many of my friends here use. 

You look at your opponent's face, then look down and hit mawashi gedan (low kick, kick/shin in the thigh). You do this 4-5 times. Then you look down and throw a Mawashi geri jodan (circular kick to the face).