Here was my strategy for acing orgo and scoring top of the class.
1. Don't prestudy.
2. Do lots of practice problems. The best book is David Klein's Organic Chemistry textbook with associated solutions manual. There are ~80 questions per chapter, so you won't run out of practice problems.
3. The most helpful technique for me - write your own "self-check" questions for problems that you get wrong as you progress through the practice material. For example, I was working a problem in which I only needed to reduce an ester to an alcohol. This could be accomplished with the reducing agent LiAlH4. However, I neglected to see that there was also a ketone in my molecule (which would also be reduced by LiAlH4, which I didn't want). Thus, I got the question wrong. After checking the correct answer, I realized I needed to put a protecting group on the ketone first prior to using the reducing agent. I then added this self-check question to my list:
"If I am reducing a functional group with LiAlH4, am I making sure that there are no other functional groups that will be unwantedly reduced at the same time?"
By asking myself these self-check questions as each time I worked through practice problems, it kept me actively engaged with problem solving more than simply memorizing a list of rules. By the time it came to the test, I would have close to three pages of these self-check questions, and I practiced them enough that I could check myself during the exam.
Hope this helps.