I have never really found there is a "right" spot to line up the Phasing ring. There are a number of things that will affect the phasing in the head of a helicopter, mostly the Blades and the Paddles.
Here is how I adjust phasing on my helis. After getting everything squared up in the head and making sure the swash travels thru the pitch range as level as possible I will then go about this.
Put the heli in a tail in hover. You want it as perpendicular to your shoulders as you can get it. Now... go into a full pitch climbout. You do not have to jamb the collect, just bring it up steady. While you are doing that apply forward cyclic to start the heli into a forward flip. Continue until you have flipped into an inverted hover. Make sure to not input any aileron during this. It needs to be pure collective and elevator as much as possible.
While the heli is flipping, watch the tail. If the phasing is correct, then it will flip straight over. If the phasing is off, then the tail will move right or left during the flip. I do not remember right off which way you need to spin the phasing ring to correct a right or left tail movement. You will quickly see though. Just keep making slight adjustments till you get the heli to flip straight over with the tail following straight in line.
Keep in mind, there are other factors that can give you the same results when doing this. If your swash is not level top to bottom. If you have a paddle that is not leveled.
*disclaimer: These are my opinions. Agree or disagree, Your Call :)
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