I did this when the children were small-decided I was going to see the best in my husband rather than get resentful over stuff. Mind you he is a decent lovely man who loves me - but it was becoming easy to feel/say things like "bastard didn't fold the laundry" instead of "thanks for the cup of tea" even if both things were happening. We still are very affectionate and nice to each other. I go by the rule that I will be as nice if not nicer to the people who live with me than anyone else in my life.
Coincidentally, I just read a piece on salon.com about this. four scientific ways to improve your marriage. two of them are:
#1Be nice as often as you can. A lot of modern relationship therapy is based on the research of John Gottman, a prolific psychologist famous for videotaping thousands of couples and dissecting their interactions into quantifiable data. One of his most concrete findings was that happier couples had a ratio of five positive interactions to every negative interaction. “That just leapt off the pages of the data analysis,” he says. It was true in very different types of relationships, including those in which the people were very independent and even distant or argumentative. These positive interactions don’t have to be grand gestures: “A smile, a head nod, even just grunting to show you’re listening to your partner—those are all positive,” Gottman says.
#4 Ignore the bad, praise the good. Observations of couples at home reveal that people who focus on the negative miss many of the positive things that their partners are doing. Happy spouses, however, ignore the annoyances and focus on the good. “If your wife is irritable one morning, it’s not a big deal. It’s not going to become a confrontation,” Gottman says. “Then when she does something nice, you notice and comment on that.” Guess what that breeds? More of the good stuff.