First of all, fill in the bubbles as you go, not at the end.
There are other ways but this is how I got a 760:
First read over the questions before you read the passage. When the questions make references to the passage note where, when there is more broad idea questions write these words somewhere next to the passage like “main idea” or “Scientists X’s Main Argument” so that you can mentally start to get a better idea of what you need to focus on. After you have read the questions and know generally what you are looking for read the passage and stop and answer a question where you have made a note. If you see where this Scientists main argument is in the passage, go to that question and answer it after you have read it. When answering question keep in mind: THERE IS ONLY ONE RIGHT ANSWER! The SAT is not trying to trick you and none of the questions are up to interpretation because it is the SAT’s job to make sure that there really is only one right answer! Knowing this, keep in mind that all other answers but one is wrong for some reason. When you are looking at an answer, never think how this could fit, always be thinking how could this be wrong first.
There are 5 different types of answers that are usually a put:
Completely Wrong
The Correct Answer
Unrelated/Some small part wrong
Correct, but too broad
Correct, but too specific
There is also the questions that have the “what evidence from the passage gives the answer to the previous question” where you should be able to link the evidence from the passages to the answers to the previous question. Another thing that will get you is that the SAT does not always have to give the best answer, they just have to give an answer that works. So looking at the evidence from the passage and using that to help decide which one is correct is very valuable because you can look at the exact evidence it is giving in the passage and asking yourself, “does this fit?”
Other than that, just try to come into the test feeling confident, not too stressed but still focused, and try to read the passages as if your very interested in them. If you can, get interested in the passages. Make sure to do some reading practice beforehand and check your answers to see what you’ve missed, and then look at the explanation to figure out what you have done wrong. When practicing do not let a single miss question or question that you were unsure of go by without understanding why the right answer was the right answer!
Another way to try and improve your score is training yourself for speed. When you can finish passages in 10-11 minutes without hurrying, then you’ll have plenty of time for the ones that you get stuck on and looking at those from every angle.
Sincerely, someone who also started in the 650 or so range.