You know it’s interesting, but I have often seen that what a person may complain about in their spouse, is often something that was first attractive to the person in the first place.
For example, While dating: I just love his sense of humor! He is always making jokes and making me laugh! Same couple, married: He can never be serious!
While dating: I love the fact that she is always dressed well with attention to every detail! Same couple, married: She is always shopping for clothes, spending so much money! We can never get out on time because she takes so much time with her getting ready!
Try to project the ramifications of a middah or personality trait, and gauge whether this is something that you can live with in a marriage! If you are married already, try to remember that that was something you knew about the other person, and try to be understanding about it.