This is a very simple meditation that could also be called "free dancing."
It is important to not feel self-conscious at all during this exercise, so this is best practiced alone. It may also help if you dim the lights and dress comfortably.
This meditation begins with small rhythmic movements and continues on into larger rhythmic movements until the whole body is engaged. To begin, move any part of your body forward and back slowly. I like to begin by nodding my head very slowly, but your hips, an arm, a foot... Anything counts in this exercise.
Next, move the same part of your body side-to-side, and find a comfortable movement that incorporates both forward, backward, and side-to-side movements. I like to bob my head in circles to feel my neck stretch and relax. Begin to move another part of your body and follow the same process into a rhythmic and circular movement.
Continue to add parts of your body to the pattern of movement, making your movements loose and circular where you can. The important element is to not judge your own movements- simply move in rhythms that you find comfortable.
The meditation ends whenever you want to stop moving, but try to engage your whole body in a sort of completely free movement or dance. This may not end up looking like any sort of dance you have seen before, as the point is not to dance freely but to move your limbs freely and to focus on this experience of your body.
This meditation is highly beneficial for those with physical anxiety or an overbearing judgement on how you move. For instance, if you often finding yourself wondering what to do with your hands in a situation this will be a very useful practice.
Ultimately, this practice will allow yourself to discover your body anew. It is impossible to not fall into habits of movement, and this practice will shake you free of those habits. Loosen up and have fun with it!
Previous Introductions to Various Meditations:
Why Practice Meditation?
Dark Night of the Soul
Exposure to Fear
Tibetan Light Meditation