If you want to prepare for the CSAT without taking any coaching, the best way is to invest in some self-study. You can find plenty of resources online such as practice tests and sample questions that will help you understand the exam format and get a feel for what kind of questions might be asked on the test. Additionally, making sure that you have an understanding of key concepts in mathematics and English language usage are also important if you wish to be successful on this exam. Creating a study plan where each day has specific goals with regard to content review is also essential for your preparation process; this way, when it comes time to take the actual test, all of your bases should already have been covered!