Black or white candle
Frankincense or sandalwood incense
Piece of paper and a pen
Water

Light the candle and imagine the flame burning away all the negativity you need protection from.  Say (you can substitute “me” for a name or an object):
 

“Hecate of Darken Moon
Grant me protection, please make it soon.
Surround me in a sphere of light,
And protect me with your awesome might”

Write what you need the protection from on the back of a piece of paper and in a heatproof container, burn it until it is ash.  

Take the ash and the herbs, and mix them with water to form a paste and rub it onto whatever needs protection (A building, car or yourself).  Throw the excess in a river or stream.