One of the best pieces of advice I got interviewing world-class musicians from many genres of music came from Rex Martin, who got it from Bud Herseth. He told me, “We have to be careful about practice, because we start to practice practicing. We need to practice performing.”
Lots of great players, when they work on something in a room alone, imagine someone they greatly admire, in the room with them, because it can motivate you not only to give your best, but it can also result in advice and perspective from that person, even if they’re not physically present. Try it!