You pendulum can be of almost any material but your string to start of with should be metal. Metal allows energy to flow through it.
To start of it might be better to stand with you feet shoulder width apart.
Your pendulum string should cross over you pinky and then on top of your index fingers first knuckle with you thumb resting on top of that.
Shuff your elbow into your hip and hold you arm at a 90 degree angle. Then you send energy from you heart down to the pendulum.
You are now ready to ask you questions. Start of with asking it to show you what means yes and what means no.
For me yes in usually a circle motion whereas No is a straight line. (It obviously works better if you cat is not in the area to play with your pendulum)
When you start ask questions you know the answer to in order to build up you confidence and when you are finished remember to thank the spirit that helped you.