Instructions
Seat yourself closer to the television and Kinect sensor than you would if you were playing a game standing up. The Xbox 360 Kinect needs to register your gestures only from your torso up. If you sit closer, you'll benefit from more accurate gesture detection.
Sit straight up and make sure that the Kinect accessory correctly senses your upper body, arms and head.
Face your palms toward the Kinect sensor when completing gestures. This will ensure that the Kinect accessory properly detects your moves and actions.