Here are the College Board's instructions.  Read them now so you don't have to later.

TERMS TO KNOW

noun, pronoun, preposition, object of a preposition, adjectives, verb, adverb,  conjunction, past participle, infinitive, gerund, subject, object (direct/indirect)

WEAPONS OF THE TEST WRITER

On ISE questions, the test writers try to hide the errors by separating its components.  For instance, they'll put the subject and verb at opposite ends of the sentence in the hopes that you won't notice that they disagree.

The testwriters can only make certain types of errors.  Each error type only works with certain types of words.  So, if you know the types of errors that apply to each element of the sentence, you'll know where to look for each kind of error.  The following grammar traps appear in ISE, IS, and IP questions.

• subject-verb agreement
• simple past tense or past participle 
• infinitive v.s. gerund 
• wrong preposition after a verb 
• wrong word 
• wrong tense 
• number agreement 
• pronoun in the wrong number 
• pronoun in the wrong case 
• pronoun shift 
• pronoun reference ambiguity 
• faulty comparison 
• misuse of adjective or adverb 
• double negative

Because the test writers are limited to these error types, you can adapt how you read and what you write to work more effectively.

HOW YOU READ

Read the sentence all the way through.  Be on the lookout for any glaring mistakes.  Then, look at each underlined word.  Determine what category of word it is and keep in mind the error types that apply to that category.  For example, imagine that the subject of the sentence is underlined.  If it's the subject, it has to be a noun.  If it's a noun, then you check for subject-verb agreement, etc. 

If you're having trouble, stick to what's easy.  Instead of struggling to figure out the error, just look for answer choices to eliminate.  If you can eliminate any answer choices at all, take a guess (even if you're not sure). 

Don't be afraid of choosing NO ERROR.  Students often get in their own heads about this.  If you know the types of errors that they're testing, and move through the sentences effectively, you will find sentences that have no errors.

WHAT YOU WRITE

For ISE questions, the only helpful thing to write down is your coding system.  You don't want to cross stuff out in the sentence because you may need to re-read it later to check another answer choice.

Don't worry if you bubble multiple A's or E's in a row. The test writers never look at how the right answers will appear on an answer sheet. The best way to solve a question is to use the information from that question.