One of the worst mistakes someone can make when cleaning a carpet is to grind a stain into the carpet, and all over the carpet, creating a larger mess than need be. If something spills onto the carpet, whether it be liquid or a dry substance like plant soil, do not rub down on the carpet. If it is dry, sweep it or vacuum the pile. If it is wet, blot the area. When you rub or push down on a spill or stain, you just push the substance all over, making the spot grow huge. You want to keep the substance in one small area and work on that only. And, because different liquids require different cleanup methods, consult a tip guide, first, like the famous Hints from Heloise, so that you use the right cleaner. For most stains, and ones that are fresh, you can use a simple water and dish soap solution. Different types of stains might require different solutions, though.