1) Learn how to accept constructive criticism and destructive criticism, too, because you'll be getting lots of it at marine boot camp.
2) Conquer your fears or at least learn how to hide them, because if a drill instructor notices that you're scared, then you're in for it.
3) You know that voice that talks inside your head...turn it into a strong, independent, "what King Leonidas would say" kind of voice...telling you to "tough it out" when you feel like wimping out.
If you can follow these steps to prepare for marine corps boot camp, then you can greatly increase your chances of getting to graduation in one piece.
You also need to physically prepare for us marine corps boot camp. What are the best exercises to do right not?
4) Do lots and lots of pull-ups...like 10 at one time at least!
5) Do lots and lots of push-ups...like 40-50 at one time at least!
6) Swim lots and lots because you'll be doing it "lots and lots" at marine corps boot camp.
7) Run 2-3 miles per day at an intense pace.