5) Get outside advice
We're all human and within our own marriages can expect to be biased and, well, a little too close to the situation to have the most rational perspective. Check out books, groups, retreats and other helping professionals and resources. It can really benefit you to learn new methods of communication and have a coach to point out when you're constructively working on something and when you're being unfair and even destructive. And hey, if all else fails just get one of these: SpatSolver—The Ultimate Argument Resolution Device
Marriage is a job that you can get better at. Like any other important endeavor in life, it benefits from effort, planning and mindful preventative measures. As the Southern California proverb goes: Don't wait for a mudslide before reinforcing your foundation!