When there is 'no delay' from the time I first see the target until it gets to my barrel, I am going to 'fully pre-mount the gun'. Head firm on the stock. My hold point is where the target quits being a 'blur'. Not where it comes into best focus, but where it quits being a 'flash'. My eyes are between the gun and the trap....hold point is ALWAYS ON THE LINE. I start my gun moving on the flash of the clay, and deliver when I see edges on the clay. The target should not pass your barrel....if so, it should be minimal. It is over very quickly......most of the work is done before you call for the target. Its quick, because it is very efficient.
That is a synopsis. That technique is worthy of a lesson or two to get into all the details and nuances. Let me know if I can help further.
Fennell Shooting School