When you feel good, you often behave well. And when you feel bad, you often behave badly, right? For example, you have a stressful day at work and when you get home, you're not very nice to your kids.
How you feel influences how you act. But it's also true that how you act can influence how you feel.
You can use this fact to your advantage by deliberately altering simple things about your behavior in order to feel better. For example, changing the muscle tension around your eyes. Or changing they way you're breathing. Learn more about this: A Simple Way to Change How You Feel.