When you're getting ready to list your home, pay particular attention to the walls. The vertical surfaces of your home usually end up being murals of all the activity in your busy family. If you have small children or pets, you know how they leave their signatures on nearly every wall in the house at one time or another. A few suggestions for tackling the worst of the smears and smudges will help you get ready for an open house. Walls painted with semigloss paint are the easiest to clean since the surface won't absorb oils and other liquids. Semigloss is preferred for the kitchen and kids' rooms. You can wash latex too, but only lightly. If you scrub latex or get it wet once too often, the paint will come off the wall along with the stains and dirt. The best way to clean painted walls is with a 50-50 solution of water and white vinegar. You can fill a spray bottle with this mixture, and then add ten drops of your favorite essential oil to pump up the grease-cutting power. Use an essential oil that's clear or light such as mint or eucalyptus. Tea tree oil is a favorite, but should only be used on white walls. Most wallpaper today is washable, and some is even labeled "scrubbable." Washable papers have a thin plastic film, while scrubbable papers are coated with vinyl, or are impregnated with vinyl. The reality is that you really can't "scrub" either one, and you shouldn't use abrasive cleaners on either as that could mar the protective coating. Clean wallpaper with a soapy cloth or sponge, using a circular motion. Wipe away the soapy cleaner with a second damp sponge, and then dry the area with a clean towel. If you need repeated cleanings, wait until the area is completely dry and begin again. If you proceed while the wallpaper is wet, you run the risk of dissolving the glue backing which will cause the paper to fall away from the wall. Dust wall paper to cut down on streaks and stains. This is especially important in kitchens and bathrooms where hot water and steam can encourage a film to develop over the wallcovering. You can also rubber-band a clean cloth over a broom head, or use the brush attachment on the vacuum to dust the wallpaper. Stains or spots on nonwashable wallpaper can be removed by rubbing a pencil eraser over it. The same goes for pencil marks. A freshly cut rhubarb stalk rubbed over a stain is often effective. Wipe afterward with a damp cloth. Test both the eraser method and the rhubarb method on an out-of-view area first. Grease stains in the kitchen are annoying, not only because they're tough to remove, but because they'll bleed through new paint and some wallpapers as well. You can try this method: Cut a paper towel into four squares. Put a couple of drops of eucalyptus essential oil on one square, and let it dry. Set your iron on low, and then press the oil-treated paper square against the grease stain for a few seconds. Repeat this process with the remaining squares of paper towel. If the grease stain is persistent, wait a few hours, and apply a thick paste of baking soda and cream of tartar with just enough water to hold it together. Let the paste dry over the stain, and then brush it away. Most crayons today are washable, but if you've still got the old kind around, you may have tough marks to remove. Try the methods described above for grease stains. If the mark is still there, scrub the area with liquid castile soap and a couple of drops of orange essential oil. This method might be too harsh for wallpaper, so you'll have to decide if yours can withstand the scrubbing. Food stains on kitchen walls are best, of course, wiped away immediately. But sometimes we don't even notice until it's "major cleaning" time. If the wall is washable (paint or paper), mix one cup of water, a half-cup of vinegar, and six drops of lemon essential oil in a spray bottle, and attack the stains. If the wallcovering is nonwashable wallpaper, or latex paint, carefully scrape away as much of the food stain as you can. Then, put a few drops of eucalyptus essential oil on a cotton ball, dip it into dry baking soda, and rub into the stain until it disappears.