I agree with everything Jeff and Sauer have said, but will add another couple of comments.
Firstly, in trickier conditions at very long range we will sometimes fire a spotter shot at a bank at a similar range and direction to the target animal, but not too close, usually 50 plus yards off to the side. The animal will usually look up but still give you time to correct, get on him and get a killing shot away. If he does bolt at the spotter shot, so be it. I would rather have this happen than risk a wind call I'm not quite sure on. I know other very experienced extreme range hunters who use this technique, and it works.
Secondly, I always err on the high side with my POI - I aim 2/3rds of the way up the shoulder not 1/3 to halfway up like I do at a shot inside say 500 yards. There is more lateral leeway with quickly fatal organs etc to hit in the top half than the bottom half. If you stray back a bit, you have the rear of the lungs, then the liver and spleen, and then the kidneys. You also have the spine all the way as an anchoring shot even if hit behind the diaphragm. Forward of the shoulder itself you have the neck vertebrae. If you hit low and back, you miss the lungs, and will hit paunch at best which is a terrible place to wound an animal. And if you're going to miss just over or under, over is best as you won't wound the animal. Just under can easily cause a smashed front leg and a lost wounded animal.
You don't "practice" on our game animals. Once you've done all your range work, "Rock hunting" in your hunting areas as Shawn Carlock says is probably one of the best ways to teach yourself to make the shots in the field, and to work out when you and your equipment are up to the task. Its also bloody good fun too!