For the past 11 years or so, I have been teaching myself how to relax and be calm.
I have always been quite a worried person, so I feel I had to learn this in order to simply have a better life with more control. I still sometimes forget how to, but each time I remember, I do the following:
An easy quick way to instantly relax the mind and muscles, causing bloodflow to spread more evenly in the body, is to do three things simultanously: relax the jaw and eyes completely, breathe deeply into belly for at least 8 breaths and move the inner gaze/attention to the feet or ground below. Get a sense of the Earth. Notice the effect.
Another way, if you have the oppotunity, is to lay down flat, do the same with jaw and eyes, and to focus on the in and out breaths in the belly. Take deep slow breaths. Imagine them as waves ebbing on the shore.
And lastly, going into nature of course has a calming effect too, even just for 10 minutes. If you cannot go outside, perhaps painting or drawing nature is an idea.
Hope this helps! I truly believe knowing how to relax and calm our selves is an important skill. Getting carried away by the storm can be both painful and result in regrets.