Tai chi practice helps to cultivate sensitivity to subtle changes in the body and beyond. This has implications for overall health and wellbeing, because you should be more able to detect shifts in your physical conditions early and fend off illness before it is too late. You can catch a cold for example and stop its development before it takes over. Years ago, in my early fifties I got shingles, which can be painful and for some, last a long time. Mine lasted about two weeks and I attribute that to catching it very early, going to a doctor and getting medication practically the first day I detected something odd. I attribute that to my tai chi practice.
Part of the reason why tai chi is so powerful for maintaining overall health and well being is due to its meditative qualities. Slowing your mind and body down with mindful movement, breathing completely with conscious intention, focusing the attention on the dantian (field of elixir) and zhong ding (central equilibrium) and moving from the center that is created, all together cultivate awareness of changes in one’s body, mental and emotional minds, and even in other people around you. Perhaps the term intuitive is applicable here. You become more intuitive, meaning you become more aware or cognizant of energetic movements beyond the material world.
The means by which you can practice developing greater sensitivity of the subtle energies is to be sure to move in the sequence that is most appropriate for taiji. That is a mind-energy-body progression. The way I have learned to practice that I find effective is to visualize the movement before actually moving. When I do that, the qi goes there in a natural response to the intention that has been set, then the body follows. This is a powerful way to focus your attention in meditative movement.