Typically you shouldn't be striking the shuttle as hard as you can. The best way for someone to learn shuttle testing is to have someone there who is confident with their own testing. Let them test the shuttle, and tip it to the correct speed, then let them test it again. Once they have confirmed, and you have seen where the shuttle should be landing when at correct speed, you should attempt to test the shuttle yourself. If it is going too far, or not far enough, you should adjust your swing until it lands where it should. Now it's just a matter of remembering the speed and angle at which you hit the shuttle. Remember to use a stroke that is comfortable to you, so that it can be easily reproduced in the future. There are also lines on some courts that show where the shuttle should be landing. The lines are roughly in front and behind the back doubles service line.