Sage is wonderful for clearing out negativity in your home or workplace. It's also good to smudge your crystals with. Do not breathe in the smoke directly its just for cleansing.
Tip: Leave windows open in a room to allow negative energy to leave the room
How to use the Sage?
Slowly walk around where you are and take the smoke to each area you would like to cleanse. Concentrate on gateway areas, such as windows, doors, closets, as well as hallways. Also concentrate on the corners of a room.
Most importantly, use your intuition. If you allow it, your space will usually inform you as to which areas need to be cleansed the most.