I want to change the subject a little.
I think that one of the causes of Shalom Bayit is that each spouse has expectations that are not realistic. She may have unrealistic monetary expections, while he may have unrealistic expectations for things at home.
I have also heard that many women feel that once they are married, they can open up to their husbands with whatever they are feeling. Well, sometimes that comes off as verbal attacks. Men might do this some times also.
I (indirectly) heard from the Mashgiach of Lakewood, that peace is not the lack of war, it is the opposite of war. War is the concerted effort to not get along and to hurt. Peace is therefore the concerted effort to get along. It takes work.