Learn from past relationship mistakes

Honesty
Be completely honest. Don't hide things. This can lead to MAJOR trust issues!

Bring on the lovey-dovey
I don't care how long the relationship has lasted, the love-dovey stuff HAS to continue! Who wants to share the rest of their life with someone who's a ice cube?

Communication
TALK. It's hard for even ME to let my guard down and talk about personal things with my partner, but it is crucial. No need to be a Chatty Kathy, but you do have to talk about other things besides just the two of you. Be open like you would with a friend.

Respect
Must have mutual respect. Treat the other person the way you WANT to be treated. Put yourself in their shoes. This is NOT one-sided, though. The other person must do the same!