Answer:
Suppose you are making a critique of a piece of art.
The first thing you may think is "I like it or I do not?"
Now, in both cases, you must ask yourself why, meaning, if you like the piece, What things in the piece are the ones you like?. Are those things subjective to you? Are those things objective, like good technique or a good story behind?
The fact that you like the piece is not enough to make a good critique, you must "break" it into parts, and analyze it.