If you and your partner often lash out and yell, odds are your lil one will too. Stay calm and collected, even when you're disciplining your kids or dealing with stressful situations, and your children will learn to mirror that behavior.
Also, a hungry, overly tired, overstimulated child is a more likely candidate for a temper tantrum than a little one who's well-fed and rested. Set your child up for success!
Source: Flickr User mdnays