The most important rule in stain removal is to get to it as quickly as possible! Rinse the stain with cold water, then proceed with the specific method of stain removal for that type of stain. However, if the garment is a very expensive one, or otherwise special to you, it would probably be safer not to treat it yourself. Instead, take it to a professional cleaner.
It’s always a good idea to pre-treat stains in some manner. Washing alone doesn’t remove most stains, and hot water or the heat of the dryer may actually set them in permanently.
Be sure to follow all instructions on the garment label when trying to remove a stain. For example, for some stains boiling water is recommended, but you shouldn’t use this method on fabrics that should only be washed in cold water. Another treatment for very stubborn stains is to wet the stain with lemon juice, then lay the garment out in direct sunlight and leave it all day; but you shouldn’t use this method on a garment when the label recommends against bleaching. In a cases like these, some other method should be selected, if possible.
Use each method for stain removal ONE AT A TIME, not in combination. If one method doesn’t work, be sure to rinse the item thoroughly before trying another. Otherwise a chemical reaction may ruin the fabric.
As you work to remove a stain, put a cloth pad or paper towel underneath to absorb the stain as you work. You want to work the stain out of the fabric, not further in, so start by working from the back side of the item. Blot from the outside edges of the stain towards the center, or you’ll make the stain even bigger.