Starting Sentence Correction today with the diag problems I've done a few times before:

Read the Sentence Completely and out loud.  What is the meaning of the sentence?

Comparison:  Are the right things being compared?
Parallelism:  Look for in every problem.  At the very least can help eliminate wrong answer choices.

Does the pronoun have an antecedent?

Is verb in the correct past tense or present tense?