Top Right is how I use it, but I dont think its the "right way".
The screen has to be in, or else the case cant protect it if something impacts it (had a phone screen break on me once because it was facing out and I ran into a countertop). Top Left does make more sense, but somehow I got into a habit of twirling my phone so its top right.
So maybe top left is the "correct" answer to protect your phone from breakage, but I still have a habit of top right.
I usually do top left instead of top right just because I tend to touch my camera lenses if I hold my phone from the top side like that and I don't want to smudge them up.