It seems to be human nature to believe that if the other person would just change, (come home on time, quit nagging, be more financially responsible, keep the home neater, be more loving) my life would be happy, I would be content.
Yet many times I’ve seen someone make an attempt to change to satisfy a complaint and the partner says, “I don’t believe you’re sincere,” or “It’s not good enough,” or “When this new behavior is consistent, then I’ll express appreciation.” Habit changes come in small bites. 
It’s smart to look at methods that help habit changes succeed. In cooperating in a habit change that you both agree would benefit your relationship, (the first step) it helps to have the person who’s habit needs to change to give you a way to remind them that doesn’t feel like nagging.  It might be a nonsense code word like “peanuts” to remind him that his socks need to go into the hamper or a gentle touch to remind her to stop back-seat driving.  When the one who has agreed to change the habit has control over choosing a reminder, there is less resistance to being reminded.
In addition, the habit-changer needs to choose a kind of reward that is motivating for him/her.  For some it may be a big hug when you notice that the socks are in the hamper.  For another it might be a word of appreciation when a trip has been concluded without back-seat driving.  Choosing the method of reward builds one little success after another until the new habit is more dependable.  Learn more about no-nag habit changing in Module 8 of Millionaire Marriage Club.
In addition, it might be prudent to look at a behavior your partner would like you to change. Do you find it easy?  Would you like to choose a reminder and a reward for making the effort to change an annoying habit?
*Free Download: The No-Nag Habit Change Strategy!