Shielding can play many different rolls in your life with psi and so it is up to you to understand and utilize the aspects of shielding that are right for you. Primarily shielding techniques are used for your protection. A shield is almost always designed to keep something out, or away from you. Do not confuse shielding in psi with what is portrayed on television where physical objects are blocked, as this is not true. A shield in psi is meant to keep energy, thoughts, and non-physical manifestations away from you. Stopping physical objects is not for shielding but psychokinesis and we're not talking about that technique in this article. There are many different forms of shields with many different reasons for using each; however since this is not an encyclopedia we'll stick to the two most common shields and reasons for shielding.
The first shielding technique I'd like to talk about is most often used by those people that are empathic and are constantly bombarded by other people's emotions, or thoughts. It is also used with great effect by mediums that need a rest from seeing, hearing, or speaking with spirits. The technique itself is referred to as a Bubble Shield though I've also seen it labeled as: Light Shield, Enlarged Psiball Shield, Aura Shield, and Broadcast Shield. Whatever you wish to refer to it as doesn't really matter since the technique is always the same.
In order to produce the Bubble Shield you visualize the surface of your body, your skin, beginning to glow with energy. When you are fully engulfed in glowing energy you move the energy, through visualization, out away from your body about 15cm (six inches). This visualized layer of energy surrounding your body will decrease the volume of energetic presences reaching you and in turn quiet your senses. A commonly found modification of this shielding technique is to program (give a visualized reason for being) the energy of the shield. In this manner the shield may be used to specifically target quieting empathic pick-up while leaving everything else as is. It is wise to know that the Bubble Shield is not continually fed energy and will weaken and disperse with use and time, both of which depend on the environment you're using the shield in. Should you find yourself in highly energetic surroundings you should forego the Bubble Shield for something with more staying power and strength.
The Defensive Shield is the ideal technique to use in situations where the traditional Bubble Shield would fail too quickly. Also referred to as a Cascade, or Continuous Shield the Defensive Shield technique can be put into action by anyone that needs that extra level of protection and/or peace.
Since this technique requires several carefully orchestrated steps it is often useful to practice the shield's creation in a quiet area before you actually have need of it. The shield itself is visualized in separate sections flowing out from the body and then back into the body at different locations. To begin you need to visualize the energy flowing out from around your waist and travelling up your body and then back in at the top of your head. Next visualize the energy flowing from around your waist and also cascading down over your body and re-entering at the soles of your feet. Finally, visualize energy flowing out from the top of your head and the soles of your feet and connecting with the cascading energy surrounding you. In this manner you have fully encompassed your body in an ever changing flow of energy that you can keep in place as long as you have the strength to. As in the Bubble Shield you may choose to program the energy of your Defensive Shield to a specific intent in order to ensure you maximize the outcome you're looking to achieve. You need to be aware that this type of shielding technique can fatigue you, because of the constantly renewed energy in it. It should not be used where a simple Bubble Shield will suffice.
Just as important as creating the shield for your protection is how to stop the shield once you find yourself out of the necessitating situation. With the Bubble Shield you may choose to: draw the remaining energy and absorb it back into yourself, disperse the energy, or just let it run itself out of energy. While the last option is the easiest, since you don't have to do anything, one of the first two choices is usually the best. Visualization of the energy layer either moving back into your body, or breaking apart is all that is necessary to end a Bubble Shield. Ending a Defensive Shield is just a matter of stopping the visualized flow of energies from your body at the top of your head, soles of your feet and from around your waist. As you stop the energy flow the cascade will "drain" back into the top of your head and soles of your feet and end the shielding effect.
What a shielding technique boils down to is your protection from energetic and spiritual happenings whether intentionally meant to harm, or not. They can bring you peace quickly and allow you to remain calm and balanced even in the most trying of situations. The bottom line is that you need to know how to shield, and now you do.