To add to what War Wagon mentioned...standing in front of the mirror with the gun at the ready position (not mounted) look at your right eye (for righties), then close your eyes & mount the gun. When you open them you should be looking and pointing at your eye. This not only gives you a check for proper mount but trains your hands, arms and body to mount the gun towards where your mind's eye is looking.
Another tip to put into practice when shooting birds (clay or otherwise) is to concentrate on a part of the target, not the entire thing...look at the leading edge of a clay or the head of a bird, then mount, point, swing, fire and follow through while continuing to look at the specific spot. By reducing your target's "size" and concentrating on that spot you have a better chance of a successful shot than just blasting at the target as a whole.
"Shoot low boys...they're riding shetland ponies in search of true grit" Lewis Grizzard