Bonus: I've also included pictures of which character I'm referring to.
1. Don't piss anyone off. This is probably the biggest thing to remember. Mainly because if you piss anyone off, that automatically puts a target on your back. In our politically correct world, people would just be annoyed at you or argue with you if you say or do something they don't like. In the Game of Thrones world, they'll just kill you.
2. Having good survival skills and knowing how to defend yourself is always a good skill. With this skill, there will come a time where it will save your life or someone else's, and then you gain an ally.
3. Don't actively be trying to claim the Iron Throne. Again, this will put a target on your back. If you want the throne, that's fine. But don't say that out loud. This can refer to quite a few characters but I'm putting Lord Baelish's picture here. No one really suspects him when they should and that's why he has survived this long.
4. Stay humble. Don't think you have what it takes to defeat a Dothraki king after you call his wife a whore. Because trust me, you don't.
5. You can't always trust family. But you can always trust a good friend. Good friends are hard to come by, don't betray them. Take this advice with a grain of salt though.
6. Just because you've known someone for a long time, doesn't mean you can trust them.
7. Just because someone you trust tells you to trust someone, doesn't mean you should.
8. When someone tells you to not trust them, take their word for it.
9. Shut everyone out and never let anyone in. Keep your guard up and you will survive.
10. Don't fall in love. I'm putting Robb's picture here because when he fell in love with Talisa, that was one thing that caused the famous Red Wedding. But looking back, a lot of characters did things for love. Jaime, Sansa, Arya, Ygritte, Cersei, Ned, Catelyn, Daenerys, etc.
11. Books are weapons.
12. Betrayals aren't forgotten by a simple, "I'm sorry"
13. Dogs are only loyal if you treat them well and feed them.
14. Don't be a bastard. Unfortunate prerequisite but last names and your blood is important.
15. Be careful who you kill. Because they might come back to life, and hang your bitch ass.
16. Just because you didn't give someone a reason to betray you, doesn't mean they won't.
17. Always lock the bathroom door.
18. Take social welfare seriously like your betrothed told you.
19. Turning to religion isn't a good idea.
20. If all else fails, go live and get drunk on Redwyne Island.