I often tell my students to “listen deeper”. The more you practice, the better you get IF you are listening to what you’re doing. It starts out simply – listen to your tone, your intonation, your rhythm. The more you listen, the more you hear aspects of your playing that are possibly not what you intended. You carry this further into dynamics and phrasing and articulation. There is no end. You can always listen deeper and hear more things to improve. And then you carry this out into the world and you notice more of the world around you – the tone of someone’s voice, a color in the leaves, a bird call you never heard before, the sound of a bicycle going past your house.
But enough of that – there’s always the Deep Listening Bot on Twitter to stir your imagination.