Side B of the New Behavior Generator.
If you are taking lessons, have your teacher play something for you. Then go home and listen to Side B of the tape. Play the piece the next morning.
Or, after you see someone playing like you would like to play, such as on a music video, listen to the tape and play the piece the next morning.
In both instances, the tape will help you acquire the behavior of playing in a manner similar to your "model."
Other tapes can also be good, such as:
Personal Genius - Listen just before practice. It will help you get into the flow state.
Automatic Pilot, Side B - This will help wire in a piece so that it is easier to play. (Side A is good if you have negative self-talk going on about playing a piece.)
Memory Supercharger - Listen before bed on days of good practice or lessons.