I found this bit on what makes a good critic at Kate’s Book Blog. The idea of self-revelation is a good one, especially when you’re describing how art affects you. It makes the work organic, opening it to further understanding. Here is Kazin:
What I ask of a critic is that he usefully show the impact on his own consciousness of another’s artistic power. If the critic cannot reveal to others the power of art in his own life, he cannot say anything useful or even humane in its interest. He will scrawl, however learnedly, arbitrary comments on the text.
From Alfred Kazin, “To Be a Critic” (1981) in Ted Solotaroff, ed., Alfred Kazin’s America: Critical and Personal Writings (2003).