Forgiveness can release you from the pain of the offense. Complain and criticize. Raise it to an art form. Make sure that each and every time your spouse behaves like a human being and messes up, you not only throw the current issue in his or her face, you also bring up every mistake ever made, in detail. Celebrate what you want to see more of.
Appreciation can go a long way.
Always put yourself first. Selfishness is a sure and rapid marriage killer. Believe that the marriage exists to meet your needs. Become offended when your needs are not met. If one of you does this, it can be fairly nice.