Box breathing is an easy skill to learn and it will quiet the agitated mind. The technique is simple. Breathe in for 4 counts, hold for four counts, breathe out for four counts, hold for four counts. A handy square visual can bring the method to mind.
This morning I was teaching a young boy at the piano. He was frustrated with keeping a steady beat. I observed that he was holding his breath. I asked him to breathe slowly for just a minute and promised that he would get through this wall faster if he would keep breathing. I noted more relaxation. He found his breath at the same time he found his beat. This month of March I have studied breathing, both in myself and also the words of others who value this essential tactile expression of mindfulness above all others. "It's all about the breathing, ma'am."
"The second you choose to mind your breath you have decided that this present moment, this very moment, is worthy of your full attention."