Getting it

The true sign of skill in tai chi is your ability to remain absolutely soft and gentle throughout your practice.
You will find that grace and fluidity emerge and you will be hard to manipulate.
Your movements will become smooth and flowing, and you can spontaneously adapt to the changing nature of the moment.
Strength will be present in your every movement, yet you will be unaware of it.

Expert students learn to feel only the movement, and not their own body.

This is called 'sung'. Until you stop being tense, this kind of skill is not possible.
Every time you move, relax. Then relax again. Repeatedly remind yourself to let-go.