For Improving Memory:
Another idea that has more to do with biology than anything else, is to play the piece you are learning immediately before going to bed. It should be the last thing you do before laying your head on the pillow. During the day, our brain stores many things in short term memory. These memories are transferred to long term memory during sleep. If you are doing anything after your practice, the memories of your practice session will tend to get overwritten by the events you do later in the day. Playing the song one time just before bed, will bring these memories to the foreground. They will be transferred to long term memory more efficiently.