This is not easy, because our ego 'judges' are thoroughly ingrained in us, but struggles abate as commitment and familiarity increase. Art becomes part of the tradition of meditation where watchfulness is essential. Whatever a person paints, dances, or sings has significance when we restrain ego's value judgments. These discoveries are similar to the meditator's experience of wonder in something that was once boring and insignificant. Judgment yields to awareness.
Criticism is essential to art.
Through immersion in it. If you are able to watch and respond to thresholds that emerge in their time, the process offers unending depth, surprises, and challenges. Change is guaranteed only if I can let go of my attachment to each feeling as it appears. New Englanders say that if you don't like the weather, don't worry, because it will change. Expression is similarly characterized by fluctuations, while ego tends to lock onto things, especially things it does not like.