Biofeedback training is not mysterious. A person who looks in a mirror and changes how they comb their hair is using biofeedback techniques. For pain relief, blood pressure reduction, stress adaptation other techniques are used to give a person feedback so they can learn how to alter automatic body responses by practicing deliberately making changes using tools like mirrors, temperature monitors, electric sensors.
Simple tools like a personal blood pressure cuff can be used to track what works and doesn’t, Mood Rings can be used to track changes in finger temperature which reflects blood flow to the extremities.
The training is designed so people can recognize where they deviate from normal with feedback until they recognize what that feels like and can use techniques without the external feedback.