Few things sour prospective buyers faster than offensive odors.  Below are the four most common offenders, and tips for ridding your home of them:

 - PETS:
Use baking soda or a urine-neutralizing product containing enzymes on accident sites.  For a deeper carpet cleaning, hire a professional (be sure to let them know pet odor is the problem).  Also, keep pets' toys, bowls, bedding, and litter boxes clean.  And pets should get regular baths and, ideally, not be home when prospective buyers are viewing your property.

 - CIGARETTES:
Tar deposits are very hard to remove from fabrics, so, have drapes, upholstery and carpeting professionally cleaned.  Also, clean hard surfaces with vinegar, excellent at demolishing those deposits.  Wash walls with a vinegar-water solution, and then give them a fresh coat of paint.  Empty and clean ashtrays - and don't smoke inside while your home's for sale!

 - COOKING:
Until your property sells, avoid cooking strong-smelling foods like fish, don't deep-fry, and cook with windows open and fans on.  Place a bowl of white vinegar near your stovetop while cooking to absorb odor-causing particles.  Lemon also works: squeeze juice into a pot of boiling water; rub lemon slices on surfaces; run a rind through your disposal.

 - MOLD/MILDEW:
To get rid of the odor, you need to address its sources, so your course of action will depend on whether the problem is a rug, a leak, or your bathroom, for instance.  But, generally, to absorb musty smells from fabrics, use baking soda; for hard surfaces, use vinegar, lemon, or hydrochloric acid, all of which are highly effective fungus killers.