smudging can be used for clearing away negativity. i recommend smudging during the full moon.
to smudge, is to burn a bundle of herbs. the bundles may contain one or many herbs combined. the most common smudge stick is sage. different varieties of sage may be used; white sage is a favorite of many. smudge sticks may also be made of copal, mugwort, cedar, pine and sweetgrass and more.
the smudge stick is burned on the end, and the smoke wafted in the direction(s) desired. many, including myself, use a large feather to waft the smoke. one traditional type bowl to set a smudge stick in is an abalone shell, but any bowl that will not burn may be used. (i recommend staying away from synthetics).
i start out smudging myself, and then each room, starting and finishing in the east. i pay particular attention to doors and windows.
when finished, the stick can be smudged out and saved to be used again.
for extra protection, you could hang a sprig of mugwort over the door.