As seen in other topics (instrument, highs & lows, sensations, convergence), your proprioceptive sensations should drive the instrument, following the path : brain > inner vibration > fingers (& embouchure) > instrument. To make the last step lighter, your fingers should stay close to the instrument keys, and the light end of your tongue close to the reed edge as well. Thinking your sensations first (from your natural breathing), while forgetting your connections with your instrument (i.e. your fingers – and embouchure for a wind player), make your fingers work out your musical idea and not disturb it.
In other words, your musical intent drives your expression, through your technique.
[Ludwig Deppe (1828-1890) wrote that tone must be produced, not by finger stroke (…) but by coordinated action of all parts of the arm.]
Ludwig Deppe was opposed to hammering the keys, saying that one should not strike but should caress the keys. (…) Each finger had to work under the conscious direction of the will. He spoke of a mental map of the entire route from brain to fingertips and stressed that, together with fingers and hands, the mind should practice also.
(…) Training the ear went hand in hand with technical training.
[Amid all the noise made by those who came after Deppe, a pianist and teacher by the name of Oscar Raif made some extremely interesting experiments.]
Raif concluded that it would be worthless in developing piano technique to attempt to augment the agility of each individual finger. The difficulty lies not in the movement itself, but in the precise timing of the successive movements of the fingers. Since timing is the product of perception and will, it should be clear that technique is initiated in the central nervous system. From there, movements must be coordinated as part of one action and governed bv our will.
(…) The finished performance must be preceded by frequently repeated, consciously willed primary movements.
Any normal bone-muscle apparatus is sufficient for the development of a high degree of technique because of the brain behind the hands.
(…) first, fingers are prepared on the keys to be pressed. Each finger then presses with a light downward movement only, never leaving its key. (Thus the size of finger movement is equal to the depth of the key). And playing proceeds very slowly, pianissimo, with the whole attention concentrated on fingertips.
The musical idea, always going slightly ahead, should stimulate technical development. If technical aspects take the leading role, there is the danger of degradation into superficial virtuosity.
George Kochevitsky, The Art Of Piano Playing