Occasionally I've taken multiple shots of a group where no one image has everything just right. I choose the best overall image and edit it using more appealing 'pieces' from other pics. A facial expression (even an entire head) is easier to edit if the replacement expression is oriented similar to the original. Changing a set of open eyes for a set of closed eyes is generally the easiest. Changing the position of an arm or leg is more diffucult because it requires the immediate background to be almost unchanged. New software is advertised to do this fairly easily, but these edits were done using Photoshop 7.