Compose an altar: place a censer in the center before an image of the Goddess.
Have a twelve inch (or so) round mirror there as well.
Ring the altar with nine white candles.
Burn a protective incense (such as sandalwood, frankincense, copal, or rosemary) in the censer.
Beginning with the candle most directly before the Goddess image, say these or similar words:
Lunar light protect me!
Repeat as you light each candle until all are glowing.
Now, holding the mirror, invoke the Goddess in Her lunar aspect with these or similar words:
Great Goddess of the Lunar Light
and Mistress of the Seas;
Great Goddess of the mystic night
and of the mysteries;
Within this place of candles bright
And with your mirror nigh;
Protect me with your awesome might
While ill vibrations fly!
Standing before the altar, hold the mirror facing the candles so that it reflects their flames. Keeping the mirror toward the candles, move slowly clockwise (deosil), around the altar, watching the reflected firelight bouncing off your surroundings.
Gradually increase your speed, mentally invoking the Goddess to protect you. Move faster and faster, watch the light shattering the air,cleansing it burning away all negativity and all lines along which the ill energies have travelled into your home.
Charge your home with the protective light of the Goddess. Race around the candles until you've felt the change, until you feel that your home has been cleansed and guarded by the Great Goddess.
When you have finished, stand once again before the image. Thank the Goddess in any words you wish. Pinch out the candles one by one, bind them together with white cord and store them in a safe place until, (and if) you need to use them again for this same purpose.
from Scott Cunningham The Standing Stone Book of Shadows