These yogas require certain physical exercises in preparation for the meditations.
Among these physical practices are a breathing technique, moving the stomach area up and down with breathing, moving one’s elbow against one’s chest, performing some mudras moving from the head downwards, putting one’s hands and knees on the floor with spine straight while stretching like a dog, massaging one’s hands.
As mentioned, the actual yogas involve meditations. For example, the inner heat yoga entails visualizing mantras moving through one’s body.
The yoga of illusory body means reflecting on the fact that all appearances in the world are actually illusory. The yoga of radiant light means then understanding four kinds of emptiness, experienced as the appearance of various kinds of light (smoke, fireflies, a butterlamp, etc.).