This is a handy technique grounded in EMDR (Eye Movement Desensitization and Reprocessing) that anyone — including kids — can use to help themselves feel better.
I’m going to copy and paste instructions from the creator of the technique, Lucina Artigas:
(The instructions as to placement of the hands here is pretty specific, but I don’t think it needs to be perfect for it to work, especially for kids.)
“…Cross your arms over your chest, so that the tip of the middle finger from each hand is placed below the clavicle or the collarbone and the other fingers and hands cover the area that is located under the connection between the collarbone and the shoulder and the collarbone and sternum or breastbone.
Hands and fingers must be as vertical as possible so that the fingers point toward the neck and not toward the arms. Now interlock your thumbs to form the butterfly’s body and the extension of your other fingers outward will form the Butterfly’s wings.
Your eyes can be closed, or partially closed, looking toward the tip of your nose. Next, you alternate the movement of your hands, like the flapping wings of a butterfly. Let your hands move freely.
You can breathe slowly and deeply (abdominal breathing), while you observe what is going through your mind and body such as thoughts, images, sounds, odors, feelings, and physical sensation without changing, pushing your thoughts away, or judging. You can pretend as though what you are observing is like clouds passing by.”
For a full explanation of the technique: https://emdrresearchfoundation.org/toolkit/butterfly-hug.pdf