Raise your knee high enough to drive your foot into the opponent on a straight line. This will enable you to increase the amount of body weight you put into a kick.
Tilt and turn your hip slightly into the kick. Again, more weight, and, a little more reach and full body commitment.
While the instep is a bat, and the toes take practice, the ball of the foot provides the smallest striking area with the most weight.
Sink your weight (bend your support leg) when you kick. This attaches you to the planet, and makes it so you are effectively kicking somebody ‘with the planet.’
Generally speaking. in doing the three things I have listed, you are attempting to align the pieces of your body and make a ‘whole body kick.’
Look, to be honest, this is just the start. I’ve got the whole skinny on kicking on my Power Kicks Course. And, get this, when you get the Matrix Karate Course I give you the Power Kicks Course FREE!
Can’t beat that with a stick.
At any rate, this article should get you started on the right way to do a Front Kick, or any kick, for that matter.