2130, one sitting, third time. I had originally gotten a 1950 and then a 2020 during the spring of my junior year. I retook my SAT in December of my senior year for scholarship purposes.
For CR, you have to focus on actually understanding the vocabulary and comprehending what you are reading. There are two parts to reading comprehension: literal language and figurative language. You have to remember exactly what is being stated and then you have to use your brain to figure out what is implied (or not implied) by the language. I improved my score heavily from my junior PSAT CR score to my senior CR score using a bunch of different study books (Princeton Review, Barrons, Gruber, official) and practice tests.
For math, know your concepts and your formulas. Learn how to translate word problems and don’t make simple mistakes.
For writing, it’s basically just using English concepts, knowing idioms, and not making simple mistakes. The essay is a huge chunk of the Writing section that affects your score. Generally, write a two-page essay using historical and literary examples. Three is a nice balanced number. Have your basic intro, body, and conclusion and you should be good to roll.