"Till death do us part" really does not convey all that a marriage should encompass.  Marriage is not a set of rules or laws that should be followed.  Marriage is a conviction, a passion to see something through...  Take some time to think about the contract you would like to forge with your spouse.  Think about the things that are important to you and then create something that binds.  Something that shows you not only care about each other, but you know each other...  Here is my list (you can totally steal some of my things below, you have my permission). :

Things in my Marriage Contract

• I swear to side with you : It can sometimes feel like the whole world is out to get you, often times the best feeling in the world is to know that someone is in your corner.
• I swear to not be a douche : You know the best ways to get under your partner's skin, promise to not use them, even when it would be funny.
• I swear to take care of myself : Your life no longer belongs to you when you get married, it belongs to your spouse.  Take care of yourself with the same care you would want her to care for herself.
• I swear to never let my pride ruin us : Pride is probably the one thing that can cause more conflict than anything else.