Shavasana is designed to give the body complete deep rest; but also to integrate body and mind. Good alignment supports the Integration and effortless focus that allow a deeper level of awareness to reveal itself. So, although lying on the floor would not seem to require attention to alignment, attention to how we lie on the floor can make a big difference in the experience of shavasana. Consider the axis of symmetry and placement of the limbs, and enjoy your best version of the corpse pose.