How can I make sure I finish the AP essay question in time?

With an average of only 40 minutes per essay on the English Literature and Composition Advanced Placement Exam, you should divide your time as follows.
Spend about ten minutes reading the topic and the passage carefully and planning your essay. This organization time is crucial. Follow these steps, and you'll know what you want to write and the order in which you'll present your ideas.   

 1. Read the topic's question carefully so that you know exactly what you're being asked to do.

2. Read the passage carefully, noting what evidence and rhetorical devices are relevant to the essay question.

3. Conceive your thesis statement, which will go in your introductory paragraph.

4. Organize your body paragraphs, deciding what evidence from the passage to use and what relevant remarks to make about the evidence.

When your essay has been well planned, your writing flows faster, the essay is on the topic and well organized, and the paragraphs are well developed.
Take about twenty-five minutes to write the essay. If you've planned well, your writing should be fluent and continuous; avoid stopping to reread what you've written.
Save about five minutes to proofread your essay. Reserving a few minutes allows you time to catch the "honest mistakes" that can be easily corrected, such as a misspelled word or punctuation error. In addition, it lets you set the essay to rest, knowing what you've written, so that you can go on to the next topic and give it your full attention.