An environment that requires much more dedication and methodology of what can be expected: study improvisation is not to sit in front of the instrument and let the music flow, but it is a continuous discovery of the different parameters of music. For best results, rhythm, melody, harmony, timbre parameters are to be tested individually. And they must be treated individually.
Piano drills I propose are so dedicated to these four basic elements of music.

RHYTHM – Exercise of autonomy on polyrhythm

(polyrhythms: combination of two or more rhythms playing simultaneously while moving at the same linear tempo)

The exercise that I propose to pianists need to develop a good awareness of the superposition of two simple rhythms simultaneously designed and associated with two hands. One of the greatest difficulties for us that we play is to try to give autonomy to each hand without a ‘pull’ rhythmically each other! It takes concentration, but the metronome helps us: all exercises are designed with a metronome at medium speed (90-120) that toghether right and left. They are not required large subdivisions unit of time but a good awareness of the pulse.
A good practice is to start with one hand, stabilize and then superimpose the other, all without using single-note chords, clusters, or timbre forms.
For example, with the two notes per beat we use first and fifth of a triad, for the three notes an arpeggio of a triad, a quadriade for four, five the first 5 degrees joint of a major or minor scale or a pentatonic, etc