Here are the College Board's instructions.  If you read them now, you can skip them on the test.

WEAPONS OF THE TEST WRITER

Besides the poorly-written essay, the testwriters will try to distract you with all the wrong answer choices.  On these questions, they ask you to improve paragraphs in four ways:

• Revising sentences - This type uses the grammar traps from IS and ISE questions.
• Combining sentences - Can you weave clauses together in the context of this essay?  Can you do it without creating more errors?
• Ordering sentences - Can you follow the College Board's paragraph structure?
• Adding sentences - What's missing that would improve the structure of a paragraph?

You can adjust how you read IS questions and what you write to focus on the kind of improvements they'll ask you to make.

HOW YOU READ

Read the essay to get a general sense of what it's about and how it's organized. You don't need to find every error or undertstand the content as well as the CR section passages. You're just looking for a big picture of the essay's content and organization.  The questions will direct you to specific problems that you need to solve. 

With this big picture in mind, read one question at a time.  Note what kind of improvement it asks for and refer back to that part of the essay.  This time, as you re-read, look for the specific problem that the question addresses.

WHAT YOU WRITE

Cross out answer choices that you know are wrong. It will keep you focused on your routine for solving problems.