I have also a backround in energy healing (I'm a Reiki 2, also BPI graduate), though a different style from Nightnurse. While Nightnurse if absolutely correct that it would take a while learning the theory (classes, seminars, and even coursework), there are some relatively simple things you can try right away.

Assuming you're comfortable with the concept of auras, the energy field that surrounds all living things (feel the Force, Luke!), try rubbing your hands together for a couple seconds, then use your open hands to "feel" the region around your patient's body. In this method you never have to physically touch your patient. See if you can feel any kind of sensation near areas where there might be disease or pathology (I feel a distinct tingling in my palms.) Then imagine your hands "smoothing" out the energy field.

You will be surprised how much you can pick up this way. I have correctly detected a person with a toothache (they asked me what part of their body was in pain, and gave no other clues), and numerous bad backs. Most of the time, the backaches immediately went away using this technique. It doesn't matter if the subject believes in this kind of therapy or not. I've gotten quite a number of surprised expressions.

You should be surprised how much you can do without training or formal initiation (which some systems like Reiki require). Good luck!