So you are saying that it would be counterproductive for a musician to attempt to analyze the physical process involved in playing (as many pedagogues insist that you must), as one should merely trust the subconscious mind to provide the means necessary for virtuosity and artistry?
In short Unconscious mind is the grand director of our body. Once you(Conscious) convey this to it, it does it with greatest accuracy just like it does everything else to make you alive. For example your immune system is taken care of by this Unconscious meticulously. If you want to correct any asthma you have, just look for cure, behind the scenes it does all to cure it, which you or even doctors can't answer it.
Here is quote from Coue's Self Mastery
In order to understand properly the part played by suggestion or rather by autosuggestion, it is enough to know that the Unconscious self is the grand director of all our functions. Make this believed, as I said above, that a certain organ which does not function well must perform its function, and instantly the order is transmitted. The organ obeys with docility, and either at once or little by little performs its functions in a normal manner. This explains simply and clearly how by means of suggestion one can stop hemorrhages, cure constipation, cause fibrous tumors to disappear, cure paralysis, tubercular lesions, varicose, ulcers, etc.
Coue believed that all effort is doomed to fail?
Coue proved it, everybody saw it. We see it daily. It is not a theory!
In that case, how would one account for many successful individuals who insist that they had to work extremely hard in order to obtain a high level of proficiency? For example, Vincent Bugliosi, the greatest American prosecutor, insisted that lots of sweat and tedious preparation is necessary to become a great lawyer.
Just believe it that whatever we've in mind, ultimately that realizes. Also thoughts can quickly change in our minds. Effort is always - working against an idea in mind. If you observe a child - he/she uses no effort. If he tired, he'll simply sit or sleep. Our society teaches is that effort is good and laudable thing.
Here is the priceless quote from Emile Coue's "Self Mastery"
People are always preaching the doctrine of effort, but this idea must be repudiated. Effort means will, and will means the possible entrance of the imagination in opposition, and the bringing about of the exactly contrary result to the desired one.
Also, how frequently should positive affirmations be said each day? Is it a case of the more you say them, the better? Or can you only say the affirmations a few times, and if you have full inner conviction in them, they should produce instant results?
I advise you to read Coue's Self Mastery
. For specific suggestions you can read "How to Practice Autosuggestion" by Harry Brooks