I posted below about working on a new shielding technique. This definitely is not something I came up with on my own, nor is it something I found online. This is actually from a book titled, "Crystals Simple Routines for Home, Work and Travel" by Christina Rodenbeck.
The book is a very quick read, but so much information is packed within it, it's hard to keep up with it all. Pair that to all the lovely pictures and this book is a great read for those really wanting to learn more about crystals.
This shielding technique is rather easy. The first step is finding a stone that you feel connected with. Or, a stone that you know or feel has very protective properties. Once you have done that, the next step is to cleanse the stone thoroughly in your choosing (smudging, running water, etc) and leave it to charge in the sun for at least three hours. However, you can leave the stone to charge for longer as you wish, as long as you use only the sun and not the moon.
One the charging process is complete, you'll want to program the stone by holding it in your left hand, imagining you and the stone surrounded by a bright, white light. Once you have that visualization, you'll want to extend the light around your body (at least 3 feet around your body). This is your psychic shield. Tell yourself the crystal that whenever you where this stone or have it on your, you shield is up and running. Then, wear the stone in a necklace or carry it on your person as needed.
Recharge your stone and reprogram it whenever you feel your shield weakening.