That old saying about preparing the canvas? It applies to your home's exterior, too. So if you want to create a work of art, gather tools to properly prep the surface.
First, clean the surface of exterior walls. You can do this using a power sprayer to aim a jet of water that will blow debris off siding. Keep in mind, a pressure washer isn't the best option for wood, as it can mar the surface. (In those cases, a garden hose is better.) For other materials, like painted siding or masonry, the washer can work just fine -- even helping to remove old peeling paint.
About 75 percent of the homes built before 1978 were painted with lead-based paint. Even if your older home has been repainted several times since then, one of those early layers is still likely to be lead-based. If this is the case, you may want to call in the professionals. If you forge ahead, do so with care. Wear a commercial-grade respirator mask and eye protection, and seal all windows and window air conditioning units, as well as dryer exhaust vents, to block lead particles from entering your home [source: Minnesota Department of Health].