You need encouragement, grace, and the guts to risk yourself emotionally. You need a modicum of technique. Robert Shaw reminds us that in music we strive for perfection knowing we fall short. I learned in college that mathematical models are either consistent and incomplete, or complete and inconsistent. I choose as a singer and teacher to strive for completeness, recognizing inconsistency as part of being human and not an obstacle to growth.
Improvement requires change in behavior, or inconsistency.
The greatest singers of our time have more bad days than the next greatest singers, who are consistently good but rarely inspiring, rarely lifting the audience beyond the scope of everyday-ness. Sammy Davis Jr. once said that what makes a professional is how he sings on a bad day. The professional knocks your socks off on a good day, but when his child is in the hospital, or when he has a cold, he will still sing well enough to justify your cost of admission. So technique remains a means to an end, the end being to know that no end exists. The moment technique becomes the goal, the art dies.