When I do shoulder press with a Barbell, I usually clean it and then sit down with it on my Shoulder Bench and then press it from clavicle to lockout. Being that my arms are abnormally long, if I did the 90 degree upper arm and elbow stopping point (traditional way I think) I literally would move it 1-2 inches and not get anything out of it.
I am able to do my bodyweight for 10 cleaning and then clavicle to lockout which I don`t think is too bad at all.
There is no one way to train thats for sure, its different for everyone and different in many circumstances.