Deep breathing, imagery, etc. Imagery is where you might visualize a relaxing situation in your mind. These kinds of techniques don't require you to go to the gym. Taking care of yourself, eat right, sleep right, make time for fun and talk to people if you're feeling stressful. There's a lot of overlap with this question and the previous question.
Relaxation is the key.
Picture your breath coming from your gut. Practice your techniques to shed that stress on the way home. While driving, you can do this relaxation breathing. Once you get home, you can go for a walk, run, play with the kids, play tennis, etc. This will help you relieve the stressed out feeling.