Some things that are universal:
In no particular order.
1) Admit that you did it.
2) Take the damn punishment.
3) Look after yourself before you look after others (they won't help you for helping them).
4) Change socks during any rest break during hikes.
5) Be first in line for water.
6) Keep yourself as clean as possible. Wash your hands whenever you can, wash your ass crack whenever you can. Wash your feet whenever you can. It's the best way not to get sick. If you can, be as close to the front of the line for shower. There's never enough time for everyone to wash properly and odds are, your platoon/company/BN will run out of shower water somewhere a bit past half way. Do not think it is cool to be disgusting.
7) Powder your feet if you can (probably will not be possible during boot camp).
8) Keep your stuff as clean as possible.
9) When you're done with your stuff, help others always.