I used to use your strategy and it didn't work. Honestly, just read the passage and concentrate. Look for these always:
Main idea:What is the main subject of the passage?
Argument: What position does the author take on the subject? What is the main purpose of the passage?
Tone:What is the author’s attitude or feelings toward the subject?
Technique: What rhetorical devices (simile, metaphor, personification, etc.) does the author use to convey his or her tone, main ideas, and argument?
When answering the questions, try to literally reiterate what the passage(s) said. It's as simple as that, don't let the other choices blind you. All they want from you is to choose the answers that the passage supports. This helped:
The SAT Reading Comprehension: Basic Principles - FamilyEducation.com