Alice and Bob are playing each other in tennis.
However their internal experience is quite different.
Alice: "I’ve got to keep my elbow straight, knees firm, don’t tense". Her experience is mentally effortful, there are lots of words in her internal monologue. She spends many mental cycles on success or failure. It takes much willpower. Her attention is very focused on individual parts. She’s micromanaging. Alice is not paying attention to what is going on right now. She’s living in the world of what should be as opposed to what is.
Bob: He is curious about where the ball is, he’s conscious of his body in space, the many things he’s feeling. He intends to absorb the whole motion, his thoughts are mostly non-verbal. conscious experience is much more static.
What's going on here? When practicing to improve in a skill you want to get as much good quality information as possible (eg: Bob). This is your raw data. Nuances you are not aware of don’t exist. They’re invisible to you. The more you’re curious and aware of your body, it’s fluctuations, the surrounds the more you experience. You actually look at reality as opposed to hallucinate it.
You get much closer to the raw sense data. Think about how your butt feels on the chair you’re currently sitting on. You probably expect it to feel like a pressure shaped like an oval. That’s how you expect a somewhat rigid solid (human muscles) to conform to the flat surface of the chair. But if you pay attention to the sensations it doesn’t really feel like that. There's more of a bundle of sensations. If you stub your toe or experience some kind of pain, asking questions like where exactly is the pain, what kind of pain, what shape can sometimes make the pain lessen or change. Sensations are neutral, your brain places this “BAD” label on particular sensations. Which are then felt as unpleasant. 
For an exercise, Try:
Throw a nearby object at a somewhat difficult target. 
First → Really focus, think about the steps, effortful, repeat to yourself what you’re going to do. Try to explain how you are going to throw it.
Second → Visualise throwing the ball a few times, perhaps mime the motion, see what the ball feels like in your hand, imagine the trajectory the ball might take, now let the ball slip out from your fingertips, were you correct about the shape of the ball's flight?
 Much of this is taken from Jonathan Blow's Introspective techniques
 This exercise is taken from The Inner Game of Tennis by Timothy Gallwey
Tags: Psychological, mostly preconceptions, tennis, seeing with fresh eyes, experience ball toss