There is no best way to train for boot camp. It is impossible for someone who has not been in the military to even fathom what recruits go through.
You just go and do everything you are told to do. You will be pushed. You will be punished. You will be tested. Stay alert. Do your best at EVERYTHING. Stand out and shine among those that are not doing as well.
Then turn around help and motivate those very same recruits that are not shining as bright. You will know when to do that, you will know how and where to do that in due time.
It is not about what you do and how you do it. It is all about attitude. A positive attitude wins each and every time in basic, and throughout a military career.