All of these listed here are habits I would fully agree with. Here are a few that work for me:
1-Find time for FUN on a regular basis (at least once or twice a week), both with your kids and without them.
2-Exercise, meditate, eat well...your body is your most important tool in life, and in being a good mother.
3-Focus on your children's positive qualities and strengths, but don't obsess over them.
4-Journal. Write out your feelings, your ideas, your dreams. Revisit them often and grow from them.

I just left my full-time job 3 weeks ago, where I lived a competing priority life as a wife and mother married to a intern just starting his residency! My son is almost 2 years old and this segment put a HUGE smile on my face. I felt that I was unhappy not giving my family 100% of my efforts. I took home 2/3 of my family's income but now feel richer than I have ever felt before. HAPPINESS is key to my success as a mother.

The things that I used to take as signs that the universe was against me--spilt milk across a set table, kids fighting over a blue crayon while I'm on the phone, a child waking up 5 times the night before I need to be up early, one brand new shoe left at the park--I decided to be more lighthearted about and laugh it off, counting it as life and the crazy things kids do. I also decided to conscientiously smile at my kids more often as a way to show that I loved them. It has totally worked! I've been practicing this for about a year now and I feel a ton happier about the daily stuff, and I know my kids have less stress because of it too. The days are much more enjoyable.