Take a black candle which has been ritually cleansed and some anointing oil which has also been ritually blessed. Do not use anything for this which has not been cleansed or blessed already. Depending on the desired result, you should choose an oil which corresponds to this end. At the time of the new moon, or when it first begins to wane, cast a circle or use your 9' cord to create a sacred space.
Place the black candle (preferable a taper) on the altar with the oil.
Have no unblessed/uncleansed tools in this ritual. Cast the circle. Call the Goddess and her consort.
Use a burin to engrave the candle with the spell you wish to cast. Now, anoint the candle using the oil. While you anoint the candle with the oil, speak these words out loud or silently
"Tonight no moon, tomorrow the first one.
Let this be eroded till my will be done.
Candle burn down to remove all ill.
Let this spell be cast by the power of my will."
And once you have anointed the candle, place it in a safe place to it can burn down completely.