If you're talking about bringing your grip in real close (about shoulder width) and pressing the bar with your elbows out in front of you, that's going to turn it into more of a tricep extension/press. If you use a wider grip and flare your elbows out, then it's going to use your shoulder more.
Neither way is really wrong, depending on what you're going for. I like to put my pinkies just inside the rings and then press with my elbows just slightly out in front of my body -- this just feels natural for me.