Something I've noticed over the years playing jazz is that conviction & mindfulness go a long way:
You can have all the hip vocabulary or technical facility in the world, but if you don't deliver that music from a place of calm confidence and apparent ease, it's going to sound stale or shaky or forced.
If you internally second-guess your note choices during a solo, or judge what you just played, or commit to a phrase with only 99% conviction, even just that missing 1% is really felt.
On the other hand, if you choose one simple idea--even just one note--and play it with 100% conviction (own it), that's going to resonate with the listener.
I like this idea, because it's all about staying in the moment, and keeping the mind from wandering. As soon as you start judging the music you're making, or doubting yourself - you're no longer in the moment, and the music won't be either.
Staying present is TOUGH, to say the least. It's something I'm always trying to work on, musically and otherwise. I love that music pushes me to develop these mental habits.
Mindfulness is tough, but I don't mind.