Taking an opinion survey of which shoulder to wear a single point sling for a lightweight AR:
1. Strap over strong shoulder, across back, under weak arm?
2. Over weak shoulder, across back, under strong arm?
I used one a lot when I had the AR pistols. I would put it around the neck and under the strong side arm. That way, the pistol would hang about belt high on the strong side....but, guess what you get used to...
Small Arms Instuctor here in the Navy and for "us" on watch we must use strong should sling arms. Very easy to transition from this to shoot at the standing, kneeling and prone. However, if I was out in the woods I would never carry like this due to losing and arm to hold the weapon in place on my shoulder. I would then heavy end down across my back. Do them all, see what is safe and comfortable for you.