This was originally written for someone who received a 1420 on the recent SAT, but I thought it could be of help to you all so I’m giving it a separate thread! 
Disclaimer/My credibility:
Nov PSAT, some of the below strategies: 1460
Studying (last week cram): 15 hours
Jan 2017, all of the below strategies: 1510
As you can see, I don’t have a perfect score, and I’ve only taken the SAT one time. These aren’t strategies that will make you immune to error, or not need studying. However, they did boost my accuracy and focus.
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I think when your score gets to about that level and you’ve already taken 6 practice tests, you should have a good idea of what the test format is. You should also know most of the material that is presented.
Since you had a perfect essay score, I’m guessing your ELA score ended up higher than your Math? If so, I had that problem too. I didn’t study for English at all, and spent all my time cramming in math problems.
Here are some strategies that don’t require studying and still helped me a lot.
Math (I received a 740)
- Always circle what the question is asking for. Sometimes they’ll ask for 2x, and you’ll solve for x and see it in the answer choices without going back to the question. That’s a wasted answer 
- Doing the easiest questions first is more of a strategy for lower scorers who don’t know all the material or can’t answer all of the questions in time. Since there’s no incorrect answer penalty, you’ll end up doing all of the questions anyway. I like to do the written response questions first so I can have more time to think through them without feeling panicked. Then I go back to the beginning and do the multiple choice from there.
English (I received a 770)
- After reading the first line of each passage, look for the questions that come in pairs. Go to the second question, the one that has evidence in the answer choices. Find the associated evidence in the passage and circle each piece. Then, go back to the first question in the set and see which of the claim-evidence pairs correspond the best. After you’ve narrowed down your choices, go back and skim through the passage to see if you missed any crucial ideas. You should be able to answer the question with relative ease.
-Annotation is a waste of time. Read the first line of each paragraph carefully, mark down trends in graphs, and circle a few important words. Go back to the questions and skim for answers. If you really feel the need to, skim the entire passage. If you have a surplus of time, read carefully. But in general, you’ll have a good enough idea to answer the questions correctly without even having to read the entire passage.
General
- Don’t underline. Circle. It’s much faster. The mental effort it takes to create a relatively straight line in combination with the lack of visibility that an underline provides is not worth it.
- Do a 2 page spread’s worth of questions at a time, in the booklet. Circle your answers. After you finish the spread, proceed to bubble them in. It saves time flipping back and forth, and saves mental effort. If you’re running out of time and feel like you can’t afford to do this, break down the sections towards the end and bubble in 2 or 3 questions at a time.
- Put all your answers in the booklet. It can just be a quick circle. It helps when you double check.
- If you’re 50+% unsure about an answer, or you’re sure of the answer but it seemed shockingly easy / effortless, circle the question so you can go back to it.
With the above strategies, I finished each of the English sections with 20 minutes remaining and each of the Math sections with 10 minutes remaining. I proceeded to give myself a mental break by checking to see if I bubbled all the answers correctly. Then, I went back to the answers I circled, and redid them. Especially with math, checking your work is a passive action that may not be enough for you to pinpoint an incorrect answer. Ignore your work and do the problem over again, preferably with substitution. Then check the resulting answer against your original answer, and rebubble if necessarily.
If you’ve done the above and you still have time, don’t bother to triple check- you might end up psyching yourself out. As long as you pay attention to the problems on your first trial without rushing them, you’ll be fine. Sit back, close your eyes, and relax until the proctor calls time. You’ll feel more refreshed when going onto the next section
If you’re going to study, drill the hardest math concepts + study the questions you think are super easy- you may find that you’ve forgotten something. But honestly, once you have a good grasp of all the information, tests are pretty psychological. So long as you don’t psych yourself out with time-wasting thoughts like “Wow that guy finished before me” / “What if I score lower than last time” / “I should’ve crammed last night”, you’ll be perfectly fine. (also please don’t cram the night before)
If you feel yourself thinking things like this, move onto the next problem and I guarantee you’ll be too busy trying to do the problem to worry.
Bonus- I’m not sponsored, I swear. But PrepScholar has some REALLY comprehensive guides to SAT prep on their blog, including important info about format and material. However, beware of their college-specific pages with the admissions calculators. The statistics (acceptance rates, test scores) are a few years behind.
Wheww. I hope that wasn’t too hard to read, and you feel that you benefitted from those tips! I tried to condense them down to personal strategies I couldn’t find in online articles but still found helpful. If anyone has their own tips you’re definitely welcome to post them on this thread. In the meantime, I’ll be (actually) studying for my second go.
Good luck everyone!