2 indicators to tell if you are doing it correctly for a beginner.....

1. The shot startles you. Maybe REALLY startles you at first.
2. Your hand will flow freely toward your shoulder like you see Dave Cousins doing, this implies you are using back tension and following through.

If the shot doesn't at least "surprise" you andyour hand stays exactly where it was when you shot you did it wrong and without back tension........

I remember years ago when I was first learning to shoot one properly I was like a grenade with the pin pulled just wondering when the stinkin thing was going to go off. [:-]Until you get a real feel for it you will have some shots that go off way too quick and otehr times you are left at full draw wondering what is going on and why isn't this stupid thing going off? LOL
Until you learn how much to preload the trigger and how to get through the shot progression properly you will have some good ones and some bad ones but you will find a lot of times even the bad ones will be in the middle. If you just let that pin float and don't try to command the trigger the arrows find their mark like they have a mind of their own.

We are not machines and are incapable of holding the pin benchrest solid in the center of the target. If we strain and try to force it to stay there or punch the trigger when the pin is in the center, then the pin has nowhere to go but AWAY from the X ring. If we allow our mind and relaxed aiming to just let the pin float then themajority of the time it is moving back TOWARDS the X ring and the majority of the time a surprise release will make the arrow find the center.
It's like magic, there are many times when I thought I completely blew a shot only to find it somewhere in the X because I just concentrated on making a solid properly executed shot rather than worry about the pin sitting dead center as steady as I could make it.
That's not saying that you should be drawing circles all over the target with your pin, you should hold as steady and as small as your body will allow, but once you settle in the middle just relax and concentrate on where you are trying to hit and don't worry if the pin is bobbing a bit........at that point just pull the shot off properly.