Have you ever really thought about why relationships don't always go so well? Are you pointing the finger at someone else right now? Be honest. I'm going to go out on a limb here and suggest that perhaps relationships don't go well when there is a trust issue. If each person in the relationship can trust the other, all other things fall into place. Communication cannot work if there isn't trust. If money is involved, things can get really bad really quick if there isn't trust. If it's a sexual relationship, trust plays a huge role. Every part of a relationship comes back to trust.
Being who you say your are and doing what you say you will goes a long ways towards creating a person that others will trust. If others trust you then you are leaps and bounds ahead on creating a good relationship!