Some exercises one can try to loosen the fingers for piano improvisation.
I want to (finally) cover the more "mechanical" patterns in improvisation soon, and to do this it's helpful if one can play with a bit more freedom in the fingers beforehand.
These exercises are not goals in themselves but should be targeted practice to allow fingers to feel more free when improvising :-)
Cheers!

Timestamps
0:00 Intro
1:06 First exercise (Precise note attack)
10:15 Modification on first exercise (weird scale fingerings)
12:34 Second exercise (Arpeggios)
22:47 Third exercise (Parallel Thirds)
27:22 Summary
28:24 Building an impro on top of the exercises