When you use the technique,
(a) you pay attention to your anatomical body part (hand, elbow, foot, knee, spine,....etc),
(b) recognize its precise location,
(c) learn its structure,
(d) understand how it works,
(e) move it, and reconnect your sensation to actual motion of the body part.
So that you'll know your body as instrument much better. This technique can improve your body usage.
Body mapping is not exactly an Adrenalin-filled hard training with sweat-kind of thing. It is reprogramming, re-calibration, of fine-tuning type of technique. It should be quite amusing, with full of discoveries.
That said, what are you supposed to do?
Let's take a foot.
First, know its anatomy and bone structure. (Google it)
[from wikipedia]
Foot is terribly important for dance. You support your entire body weight on such a small structure. It is amazing.
Next, recognize there are three arches in a foot. Each arch allows you to balance and to move. Three together, they work like a tripod.
Move your foot (like, lift inside/big toe, lift outside/pinky side, lift all fingers, rotate clockwise, counterclockwise, etc).
Recognize the motion and connect your sensation to your command. You'll notice some exercises are easy for you, but others are difficult or un-smooth.
Playing rock, paper, scissors with your foot is one of these exercises.
A dancer's primary instrument is his/her own body. Much like a violinist knows about violin, you should know how your body works, and study it to use it efficiently.
There are many techniques for dancers. Body mapping is one of them. This kind of techniques separate professional opera singers and recreational Thursday Karaoke people, or separate serious dancers and dance enthusiasts. You can tell.
Beauty is in the details....details that are made by techniques.
One of my summer projects was to collect these techniques.
