Here is a tried and true process for approaching critical reasoning questions:
Start by reading the question stem to determine the question type (i.e. Weaken, Strengthen, etc..). Your strategy will depend solely on the question type.
Read the Argument
Pay careful attention to the pertinent information as determined by the question type. For example, in a paradox question, it is crucial to identify and understand the paradox before reading the answer choices.
Before reading the answer choices, take a few seconds to recap your understanding of the pertinent information in the passage. If you complete this step, then there should be no need for you to reread the passage.
Read Answer Choices
Use the process of elimination.
Review (After the Test)
Jot down a summary of each sentence and categorize it as either context, premise, counter-premise, conclusion, or counter-conclusion. This exercise will help you develop a deeper understanding of the arguments that you encounter on your practice tests.