The first step is to establish which way the pendulum will swing for 'Yes' and which way for 'No'.
Hold the chain of the crystal and steady the pendulum. Ask simple questions, with a simple yes or no answer, that you know the answer to. The pendulum should swing; note which way it moves for yes and which way for no. A circular or diagonal swing is often taken to mean 'don't know'. Now ask the pendulum questions that you would like to know the answer to.
If you need your pendulum to give you the answer to a decision that you do not want your subconscious to influence, such as whether to take a job in a different part of the county, write the options on several pieces of paper. Screw each piece of paper up into a ball and mix them up so that you don't know which one is which. Hold the crystal pendulum over each one in turn asking a pertinent question.
For example if you have had a job offer and are thinking of moving the family to Cornwall write Cornwall on 2 pieces of paper and your home town on two more pieces. Screw them up into balls. Hold the pendulum over each piece of paper in turn and ask a question such as 'Which decision will be for the greater good of me and my family?'.
Note which way the pendulum swings to help you gain insight into the decision you should make.