Be honest
I believe this is the most important aspect of a true relationship. If you aren't honest you don't have anything real!

Lie when necessary
If you cannot figure out when it's okay to lie in a serious relationship then maybe you should just buy a dog!

Don't drink all the milk
This rule applies to everything. Don't hog all the milk, soda, cigarettes, beer, weed, or whatever it is that you both enjoy. Think about the other person for once!

Drink all the milk
Sometimes in a relationship you need to put yourself above your partner. It's not always about them, sometimes it has to be about you. Stop being a doormat!

Be yourself
If the person you are with truly loves and enjoys your company then you've got it made. Don't take advice from people that don't know you or your partner about your relationship. Especially from the Internet!!