At the end of lessons I always ask, "Do you have any other questions?"
Almost all of my students always say, "No." But, I have one who usually has a good question either about repertoire, posture, technique, or practice.
Today he asked me, "What should my mindset be while practicing?"
Obviously, it's a very general question, and, as I told him, mindset shifts throughout a practice session, but what would your answers be to the question?
I rambled for a while while trying to answer his question, but I think the heart of my answer was to "trust in the method, don't allow frustration to dictate how you practice."