I have an idea. Why not build good practice habits that carry on into performing? Why not build the embouchure and technique and excersize our minds and bodies to a trained condition where we can just be comfortable in what we can perform...and then do it as well as possible? Why not learn to be comfortable enough with ourselves to realize we will never be perfect, and when imperfections show up we won't dwell on them, but continue enjoying that which we do well? A brain is capable of one thought at a time. Multitasking requires rapid alternating of thought initiation. Mind 2 may be swinging away having a lovely time...til he hits a clinker...then mind 1 jumps in with an "I told you so. Do it this way."
Enough talking, just DO IT.