I burn dragon's blood incense or Frankincense and smudge the room from top to bottom, including the closet. If you want to make the ward a little stronger, you can make some holy water (a few sprinkles of salt in a cup of water and ask the god and goddess to bless the mix will do). You do the same thing as what you would do with the incense - sprinkle some on each wall, including the closet.
If you want to do a third warding of the room, ringing a bell in each corner of the room will suffice. Normally I don't bother and just use the incense :) When setting up the ward, I envision a two way mirror. I can see out, but no one outside will be able to see anything except for a reflection of themselves.
Hope that helps :) Good luck!