The YES / NO coin is a simple aid for situations where choosing between two options feels difficult. One side of the coin reads YES and the other NO. The result of the toss can provide a direct answer or help you notice which result you were hoping for while the coin was in the air.
Formulate a question that can be answered with yes or no, then toss the coin. As well as noting the answer, pay attention to your immediate reaction. Relief, disappointment or the urge to toss again may reveal which option you are already leaning towards.
A coin toss and the answer it suggests do not replace your own judgement.