"The Mirror Protection Technique", is an excellent energy exercise and variations of it have been practiced for thousands of years.
This is a simple method of grounding and balancing, which can be developed into a strong protection. It is done with intention.
Breathe in deeply, and release all tension as you exhale. Do this a few times, allowing yourself to relax as you do.
If you feel tense, at this time do a full relaxation. To do this, start at the top of the head, consciously relax it, then move down to your eyebrows, eyes, etc, and at each point totally relax the area. Continue down through the throat, the lungs, heart, arms, hands, torso, abdomen, legs, feet, etc.
When you feel relaxed begin to breathe any tension, pain, etc down into the earth. As you breathe in, bring up the earth energy from deep in the center of the earth – firey energy. Let this energy come to rest in your heart center.
Next breathe up to the sky, and as you breathe in, bring down sky energy (sun, star, cosmic, or sky) and let that fill your heart center, mingling with the earth energy.
Let both of these energies mingle and then fill your entire body. Take your time. When your body is filled with light and energy let it expand beyond the boundaries of your physical body, and let the light and energy fill your aura - about 6-8" ovoid (egg shaped) sphere surrounding your body.
The next step is to harden the edges of your light filled ovoid shaped aura, like an egg shell, with the intention that it will act as a protective screen, filtering out any negative energy that comes toward you, but letting in any positive energy.
If you have an extreme situation, with a need for further protection, mentally place mirrors on the outside of your protective screen, around your aura. These mirrors face outwards, and reflect anything negative or harmful back into the universe, where it will dissipate harmlessly. You can programmed the mirrors to allow positive energy in, with your intention.
Mirrors can also be placed around your home, your car, and those you care about.