1. Catch it while it's fresh, when chances of removal are 75% better. Don't iron or hot-air dry until the stain is gone. Heat will set most stains.
2. First blot up all the liquid and scrape up all the solids you can. On a large liquid spill you can use a wet/dry vac. Be careful not to spread the stain.
3. Test any chemical you intend to use in a hidden area to make sure it won't discolor or damage the surface.
4. Apply spotter and work from the outside of the stain in, to avoid spreading. Blot, don't scrub; strike with the flat face of a spotting brush if needed to help break up the stain.
5. Rinse chemical spotters out with water, blot the area dry and feather the edges. Brush or fluff up pile or nap.
6. On carpet and upholstery, put a thick pad of toweling over the spot, weight it down with books, and leave it there overnight to "wick up" any remaining moisture.