Pausing for just a bit and combining that pause with a slow, deep breath can make all the difference. If home life is hectic you can try pulling over a block or two before your house, turning off the ignition and just taking a moment for yourself. Just a few slow deep breaths can lower your blood pressure, give you a sense of calm, and smooth the transition from work to home. John Kabat-Zinn is a Professor of Medicine Emeritis at the University of Massachusetts Medical School and founder of clinic that focuses on equipping patients with skills to improve their ability to heal from, prevent and cope with medical conditions ranging from psoriasis to cancer. He suggests that we use anytime we put the keys into the ignition as a cue to pause and breathe. Richard Carlson, PhD, the author of the Don't Sweat the Small Stuff series of books, suggests that we do this for a few minutes for every hour that we work. He makes a convincing case that when we cut down the harried pace and take the time to pause and breathe that our productivity as well as the quality of our work is likely to increase.
As someone who works regularly with parents, I notice that simply pausing before responding to something that our children do or say decreases problematic interactions and increases parent effectiveness. In conversation in our culture we tend to rush in to have our say, often thinking about our response as we try to listen. I'm familiar with this one because I can have a tendency to jump in too quickly. Experiment with pausing and taking a breath after the person you're talking with finishes their thought.
For more information on breathing to reduce stress (and on mindfulness) you might begin with one of Richard Carlson's books from his Don't Sweat the Small Stuff series. To explore the link of breathing and mindfulness with medicine and health, John Kabat-Zinn's Full Catastrophe Living can be a nice place to start. In...and...out. Slow and easy. Once you've experimented with that and maybe put up a couple of post its to remind yourself to use these skills (bathroom mirrors, closet door jamb, on the fridge), you can check out Pause and Breathepart II