I recently started tilting my shoulders as I throw with the figure 8 style and my accuracy and power have much improved.  

when I say tilting the shoulders I mean at the begining during the wind up i'd point my left arm up, my rip cage on the left would feel a stretch and my left shoulder almost touch my left ear.  As I go through the motion my shoulders will see-saw and my right shoulder come up.  At the release my left leg, right shoulder and the pocket are all extended and inline, this means the ammo would be something like 12 feet above the ground when I let it fly.

It's funny, I have been doing that on my serve in tennis all along but have only started slinging with the same technique.  

I hope this may help you too!

Wow, so you can hit a plastic bag at 200 yards now?   

Don't we all.