All items pick up a charge of positive protons or negative electrons. The problem is that as these items gain a charge, they will seek to find equilibrium naturally. This means that if there is anything which comes into contact with it that is a good conductor that it will help to move the electrons from the charged item to a ground.
Charges can be produced when two objects are rubbed together. This is called a static charge and means that the object is loaded with electrons and ready to get rid of some. By grounding the object through a grounding object, the electrons will flow through the conductor and to the ground.
Conductors versus Insulators
The important thing to understand about items is that there are items which are good conductors as well as those which are good insulators. Plastics and glass are both examples of good insulators. Rubber is also a good insulator. Using things like metal and organic materials create good conductors. This creates a specific danger from those working in an environment in which people are working with electronics or other materials which can be damaged by the electrons moving through the conductor.
The best way to make sure that you will be able to protect items in an ESD environment is to use grounding ESD equipment like a bench top or overhead ionizers. Grounding cables and other conductors can help in making sure that the items you are working are grounded at all times.
Wearing rubber soled shoes or standing on rubber mats will help in offering protection from your body becoming a conductor for charged objects. This is because there is nowhere for the charge to go. Using the right grounding equipment and also by using the right kinds of clothing will allow you to be able to stay safe no matter what you are working on.