They can be made from many forms of crystals; selenite, fluorite and clear quartz just to name a few. One of my favourite is selenite.
To clear the auric field for your self:
In one hand place the wand or crystal that you will be using. Place the opposite arm out to the side.
Start with the wand on the opposite side of the top of the head. Moving it downward toward your arm on top, around the hands and underneath the arm.
Following down the side of the body towards the feet. Under the foot and up the inner leg to the other leg and down again to under the foot.
Change hands. Repeat the other side. Then run the wand in front of you from head to feet.
Do this with the intent of the back side also being cleared. Unless you have someone to assist you they can run the wand from the back from head to feet.