A lot has already been covered, however, I am a Sergeant getting out in a year and here is my advice.
1. Get in shape and stay in shape. In the infantry it is Sergeants and Corporals that will own your soul. If you can hang in PT then you will get a small bit of respect. We are tough on you but most of us actually care. I don't like sending Marines home in body bags. "The more you sweat in peace the less you bleed in war"
2. Be prepared to learn a lot and be the resident duty expert with your assigned
weapons system.
3. Fully devote your life and CONFORM. Do not come in with an attitude. The Marine Corps has changed a lot recently and we can no longer lay hands on you, however, there are another million ways to make your life miserable. Even if you only stay in 4 years they will be a much less painful 4 years if you accept the fact up front that it will suck and you adjust your attitude accordingly.
4. Be willing to learn.... I cannot stress this enough. Knowledge and the skills that come with years of practice will make you efficient in combat.
5. Don't think that when you join you will go "Recon", MARSOC, or anything else. If you have what it takes... and they want you.. then they will take you. Do not hang all your hopes and dreams on this one job though outherwise you will be a ****ed off useless terminal lance or worse at the end of your 4 years.
6. It will suck, however, you will get paid to shoot, potentially go kill things, and other things that I'm sure sound glamorous to you.... keep in mind that the majority of your time will be spent in roach infested barracks where the hot water and AC never work at the same time and you will either be cleaning your room, learning knowledge so you can spit it out verbatim as it was written in the book, or doing Gunny or SSgt's working parties. Suck it up.. working parties and other menial labor are actually written into your contract that you sign at MEPS.. and all your leaders have spent their time swabbing the decks..
7. Don't be weak
8. Don't be weak
9. Dont be weak
10. Actually enjoy where you are stationed find things to do on the weekend other than sitting in your barracks getting wasted and playing video games.
11. Improve yourself and learn at least one thing new EVERY DAY
12. Don't try to duck out of your contract. Be a Man.. You sign it.. That is your word.. Make sure that it is good.
14. Do NOT get married in your first 4 years no matter HOW much you think you love that stripper that you met at Tobie's last night.. Its never a good idea and she is probably already married to another Marine who is deployed, or is a SgtMaj's daughter.. Neither are good options.. with short life expectancies
*** I Purposefully skipped the # 13