Scrying is an ancient tradition of gazing into certain objects for the purposes of divination. The most commonly used scrying object is a crystal ball, yet over the years more and more emphasis has been put on using the pendulum for divinatory practices.
Often when first starting out, it is best to meditate to get results. By asking a question and directing a large amount of energy into finding that answer, you will normally be granted a vision/image faster than what you would do if you just left it to happen gradually.
It is possible to scry with more than one person using one object, such as a crystal ball, however I would suggest doing it on your own until you feel a more comfortable before working with others.
There are different surfaces which you can use for scrying;
Water in a dark bowl
Mirrors
Crystal Ball
Tea Leaves/Coffee Grinds
Fire embers