Smudging creates a 24 hour shield of protection and will drive most anything detrimental away, unless it is already attached to you. The instructions below are for white leaf sage.  I purchase white leaf sage through Matoska Trading Company, which is listed on my Recommended Resources Page

To smudge, simply untie the string (if bundled) and break off a couple leaves.  Use only a fire-proof container, such as a bowl with a layer of dirt or sand which you can comfortably carry in one hand around the area you wish to sage.  This bow will catch the embers and ash as you go.

Light each leaf until it is solidly burning around the edges, then blow out the flames.  This creates the smoke for smudging.

You can leave this in the middle of the room to burn in your fire-proof container to slowly cleanse the space, or you can do an active smudge, as described below.

I always recommend cleansing with sage on a very regular basis – at least once a week as possible.  Some people have strong reactions to the smell of burning sage, so that might affect the ability to open windows/doors to allow the smell to vacate quicker.  Sometimes burning incense afterwards, or spraying lavender water, etc., can help, but you don’t want to perfume the room directly afterwards.

Should you find yourself under energy attack, immediately light some sage and allow it to cleanse your space.  This will give you breathing room to analyze the situation and determine appropriate actions.

Active Smudge Technique:
Beginning at thecorner of the room, fan the smoke into the corner of the room making sure to cover the area where the wall meets the floor and the wall meets the ceiling.  Turning slightly right, begin to walk around the outside of the room, fanning the smoke out as you slowly walk around the room, covering all areas of the perimeter, and especially the corners of the room.  This will create the outer barrier of protection.

Once the barrier has been created, fan the smoke throughout the room and into any spaces you feel may need extra help – especially closets, cupboards, dressers, under the beds, etc.

You can then continue throughout your house, including your basement/attic should you choose, or if you have cleared what space you needed to, let the leaves burn out naturally.

It is possible to lightly wet the leaves to dampen them so the burning ceases, but please note that you will need to allow proper time for the leave to completely dry out before you attempt to light them again.