The mirror represents the Divine, reflected in worldly form. Mirrors are believed to reflect the soul. http://www.occultopedia.com/m/mirror.htm
When you wake up in the morning imagine yourself standing and place mirrors facing outward around you, and then ask the mirrors to surround you in a complete circle to protect you from any and all negative energy sent in your direction.
This will reflect the negative energy back on the sender. There are no harsh words or arguments the person will simply go away or they can't come near you. Evil can't stand to look at themselves in the eye, so it has to turn away. Evil has to reflect back on the source.
Mirrors are like a magnet. The mirrors draw in more goodness to you - more love will come, more beauty will come, and more opportunities will enter your life. Blessed Be!