A Simple Practice - Rhythmic Movement

This technique requires you to have an object that you can pass from hand to hand. It could be a ball, a lip balm, headphone/case...
By practising this technique you are engaging in bilateral stimulation which can be very supportive when you are feeling stressed and reactive (sympathetic state).

If you enjoyed this technique, you might also find these helpful:
A Simple Practice - Tense & Release
A Simple Practice - Tapping

Everyday Mindfulness - Less Stress, More You.