(from the FP link)
Just to be clear, I don’t want it to be assumed that a technical knowledge of harmony is necessary for making harmonically interesting music.
You absolutely don’t need to be able to play an instrument to explore this world. I think maybe as a kid I thought it was essential. Some of the best musicians I’ve met can’t play an instrument. Many of my favourite musicians wouldn’t consider themselves to be technically sound. But those same people can have an incredible sense of harmony.
Even though I do have that technical grounding, there’s a process I use that’d perhaps be useful for people who think they struggle with chords but still want to come up with something that interests them. Basically I record lots and lots of chords completely independently of each other. The overall key doesn’t matter, they can have no relation to each other whatsoever. Then you sample these chords, lay each one out on a key of a keyboard and experiment with playing them back in a different order to see if a certain combination sounds nice to you.
That’s just one way of exploring new progressions that you otherwise might not have come across. For me, as someone who can get around a keyboard, I still might not come up with any of those combinations naturally. I’ve got those go-to voicings as you say. I end up slipping into certain progressions. But this technique can get you exploring harmonic progressions that you wouldn’t have thought up, whether you know about the theory behind harmony or not.
with normal keyboards i find my hands physically playing progressions that are familiar
with earthsea (ie grid of chromatic notes in stacked fourths) a completely new playing style emerges and chord shifts i never would have done just spill out in the best ways.