How I came up with it
For a few months I have been working with a metronome on inverted triads, by scales, half-steps, steps, 3rds... On this day I stopped the metronome and started to play freely with the triads, trying to find a way to make them sound good chromatically, creating chord progressions, mixing minor, major, diminished and augmented, starting on the root, the 3rd or the 5th. Then I started up the metronome again!
Make up your own
The video I made is just an example, you can copy me if you want, and then start developing your own progressions. Half steps, steps, 3rds, whatever pleases you most. You can also, starting on the same note, play the root, the 3rd or the 5th. It will train your brain and fingers in a different way.
It works on chord changes too
This exercise can also be useful to memorize chord changes, or to work on ii/V/I. You look for the closest starting notes, while underlining the progression.