Buddha-nature gives rise to all forms yet it is neither a form in itself nor separate from form. It manifests from one moment to the next, and to try to cling to it is to try to capture the liveliness of a river in a teacup. Every few moments we can refresh our awareness of the five senses. Alternatively, I can become aware of my feet on the ground or my behind on the chair. In this way I give myself into Form, sink into Form, become absorbed into Form.
Sensations are pleasant, unpleasant or neutral.
This is the subjective experience of them. In terms of our behaviour it is movement towards, away from or neither towards nor away from something. Sensation acts as a motivating force on the instinctual level. It moves us away from danger or an undesirable situation, and towards things that are conducive to our well-being, rather like a cat moves from a cold spot to a warmer place. But if the warm place becomes too hot, vedana will arise and the cat will move to a cooler spot.