Study the book, painting, poem, movie or other text you with to critique. If it’s a book, read it through from beginning to end. If it’s a movie or a painting, observe it closely at length. Pay attention to your responses: the thoughts and emotions evoked by particular elements, the way the text adheres to broader artistic trends and the underlying truths or points which the text seems to be making. Jot down notes encapsulating these feelings and mark particular passages in the text to which they refer.
Gather your notes and organize them into a few clear notions representing your overall thoughts on the piece and the specific evidence which backs up your points. The stronger and more concrete you can make your points, the better your critique will be.
Write an opening paragraph, stating the name of the text and its creator, as well as a brief encapsulation of the points you intend to make. Try to make your introduction compelling, with solid hooks to draw your readers into the rest of the critique.
Write the body of your critique, focusing on your main points and using evidence from the text to back them up. If you’ve adopted a classic five-paragraph format, your arguments should comprise a total of three paragraphs. If you have more space to work, you can expand your arguments as much as you like. Always maintain an objective tone, and use concrete evidence to support your points.
Summarize your arguments and wrap up your critique with a proper sense of closure. In a five-paragraph format, your conclusion should only take one paragraph. You can expand it if you’re writing a longer piece, but your intention is to finish the piece with elegance rather than extend it unnecessarily.
Set your critique aside for a little while--anywhere from a few hours to a few weeks, depending on your deadline--to give yourself some perspective. Then go back and revise it: fixing grammatical errors, improving sentence structure and polishing the critique until it is as good as you can make it.