Very simple. I have gone to many show and watched people teach pendulums. What I always fine is that people are told to keep in perfectly still and they will be told one way is yes another way is no and or they use a chart. I am not saying that this does not work. It does however it is limited. It is far better to just let it swing. Watch the pattern it makes. Find what is negative, positive, neutral, magnetic, toxic. You get the idea. Watch the pattern mark it down. Remember that you are communicating with your subconscious which is connected to your higher self when you are working with it. This is an over simplification and usually this is taught as a class over several nights, but this is a start.