Stress usually arises when our thoughts are in the future or in the past. We imagine all the bad things that could happen or what bad things have happened in the past.
In the present, however, in the vast majority of cases, we are not exposed to any acute threat. That's why the more we succeed in coming back to the present, the less stress we feel.
One way to do this:
Grab a glass of warm or cold water. Feel how the glass feels and what temperature the glass has with the water in it. Slowly bring the glass towards your mouth, feeling the movement of your muscles and arm. Very carefully, take a sip of the water into your mouth.
Don't swallow the water right away, but feel how it feels in your mouth. What temperature it is and how it tastes.
Take your time for it.
Then swallow a small sip of water. Feel the water running down your esophagus. Feel how the coolness or warmth of the water feels in your stomach and in your body.
In this way, slowly empty the glass. Use all your senses as intensively as possible.
The exercise comes from mindfulness and brings us out of our stressful thoughts and back into the present moment.