I'm left eye dominant but right handed. I shoot long guns and bows from the left. I shoot handguns with my right hand.
When I was in high school I went shooting w/ my best friend and his girl friend. We were shooting 22 pistols. His gf shot well, but there was something odd about her shooting. We finally figured it out......She was shooting right handed, but was aiming w/ the left eye. As was pointed out earlier, it not which hand one's dominant w/ that determines which side one shoots from, but which eye is dominant. And, yes, it's a subconscious thing. Before most kids ever shoot a real gun, they've already had years of handling toy guns so that it's already been determined which side they naturally shoot from. There are some successful shooters who shoot well w/ their non-dominant eye, but it's difficult to do consistently.