Read and do tons of practice. The best resources will be AAMC material. Make sure you try to do some CARS practice every day, since you'll only get better through practice, practice, practice.
Everyone has their own way of reading and unique strategy for CARS. Through trial and error, you should first find your own strategy that feels comfortable. Then, use third party resources to practice timing and AAMC materials to memorize their logic. Khan Academy is a great place to start, if you don’t know anything about CARS.