fast high kicking

I am in points style kickboxing for about two years now, my problem is i find my kicking is much to be desired. I do streching at home alot but it does'nt seem to be geting any better, i very rarly get a headshot in compition or training.
can any body shed a light on why my flexiblity is not geting any better and how to combat the problem.

Kicking high comes from the knee, point your knee where you want the kick to go and snap your leg out and back hard and fast.
Two simple things you can try when warming up your legs are:
very loose and fast, snap your leg back to hit your bum then thrust it out like a front kick except with toes pointing down, this develops speed.
Then raise you knee straight up aiming to touch the chest, again alternating very fast, this should help with the height. Do it over and over again as a warm up.
Then start kicking the bag or shadow sparring.
Otherwise concentrate on low kicks, smash the body and legs until he cannot walk and then finish with punches.

Are you stretching static or dynamic. Static stretching won't help you kick higher, while Dynamic will.

Sitting at home in a splits position for hours won't help you kick people in the head. Instead kick for hours, kick high and kick lots, and do it often.

This is all my opinion.. blah blah..

in the club we mostly do dynamic streching swinging legs side to side in various positions etc at home i have been trying boxer splitz i have a punch bag at home and kicking that would be active streching but i limited to how high i can hit it