The most important rule for cleaning any stain is to clean the spilled matter immediately. If you don't act right away, you risk ruining your carpet forever. If you spill something on your carpet, grab a cloth. First, clean up any solid matter, then blot at the stain until you've lifted as much of the stain as possible.

If a considerable amount of liquid has been spilled, wicking may occur. If you've ever cleaned a stain and had it reappear a day or too later, your carpet is suffering from wicking. This means the liquid has pooled at the bottom of the carpet. Even though you blotted up the initial stain, you only cleaned the surface. Eventually, the liquid works its way back up the fibers to the top of the carpet, causing it to look like the stain has reappeared. To prevent wicking, cover the area with a thick cloth and weigh down with books. Leave overnight and remove the stain as normal.