I ran across a blog by The Simple Green Frugal Co-Op about getting stains out of clothing. It's something that I think is a great resource to have up in your laundry closet ready when you find yourself with an especially rough stain. I've copied her entry for you reading pleasure:
It makes good sense to look after your clothes to prolong their useful life as long as possible. As a mother with three young children though, I have a constant battle with a variety of stains on their clothing! So I thought today it might be useful to share some methods for removing stains from machine-washable clothing, using commonly available ingredients. I keep a notebook to jot down methods as I come across them in magazines, books or the internet, and asterix the ones that work well to use next time. As always, use your judgement when spot-cleaning any item of clothing and if you think it might not be colorfast, test a small hidden area first (like a hem) and be as gentle as possible with more delicate or printed items.
I also try to avoid using methods which require specialised products like dry-cleaning fluid or white spirits as two of us have very sensitive skin, and for environmental reasons I prefer the simpler, the better. Usually, my first line of defence for dried stains is to soak in an oxygen bleach prewash such as NapiSan or OxiClean (although I use a cheaper generic version of these), and then move on to other stain removal methods for persistant stains, while the garment is still wet.
Firstly, note that all spills should - ideally - be seen to as soon as possible for the best chance of removal. When that isn't possible, or you don't have the time (or the energy) to deal with it, rinse the item in COLD water and leave it to soak until you can get to it.
Secondly, heat will invariably set stains, making them very difficult, if not impossible, to remove. If you miss a stain when you are washing your clothes as normal, but notice it when removing it from the machine, deal with it while it is still wet. The heat from drying the item in the sun, in the dryer or ironing it, will usually set it.
Thirdly, if you can, work from the back of the stain to the front so that you don't accidentally force the stain further into the fabric. For most clothing items therefore, turn them inside out and rinse from the back. Treat delicate items with appropriate care; don't rub vigorously.
Lastly, if you can't remove a stain, don't throw the garment away immediately - it may be possible to save the garment with some creative sewing! Cover up stains on children's clothing using applique, fabric paint and buttons. Oh and a word about hairspray and perfume - these are commonly discussed online as being good for removing certain stains, but it is the alcohol in them that does the job. Go for rubbing alcohol in preference if you can, as hairspray and perfume contain other ingredients which can make the stain worse in some cases.
Ballpoint pen: Cover fresh stains with salt to absorb as much of the ink as possible, and then soak in milk before washing as usual. If you know that the fabric is colorfast, you can use a paste made from cream of tartar and lemon juice. Apply to the stain and leave for 30 minutes before rinsing and washing. If you aren't sure, test the paste on a hidden section of fabric like the hem, first.
Beetroot: For fresh stains, rinse as much juice from the item with cool water as possible. Then soak a piece of white bread in cool water, place over the stain and leave to absorb the stain. Wash as normal in cool water. If it has dried, rub the stain gently from the outside edges inwards with glycerine, or try soaking it in white vinegar. Rinse and wash as normal.
Blood: Wash as much of the stain out as possible with cold running water. Rub the remaining stain with a bar of pure soap until removed, and launder with your normal powder or liquid in cold water. For dried stains on colorfast items, soak in cold water first to loosen the stain, then apply a paste made of 6 tablespoons baking soda and 1/2 cup water. Work it in a little and leave to sit for 30 minutes to an hour, then wash as normal in cold water.
Chocolate: Rinse in cold water, then scrub with a cake of pure soap and cold water to remove the brown stain. Then to remove the oil stain, rub with a cake of pure soap in hot water. Rinse and wash as normal.
Coffee and tea: Soak in a solution of 1 part vinegar to 2 parts water. Wash on a cold cycle and hang in the sun to dry.
Crayon: Mix two drops of tea tree oil with one teaspoon of dishwashing liquid and then massage gently into the stain with your fingers. Rinse and wash as usual.
Curry powder/ turmeric: Wipe with a small amount of lavender oil before washing as usual.
Fruit juice: Wash in white vinegar and then hang in the sunshine to dry. Many fruit stains are UV sensitive and will break down with exposure to sunlight. Dark fruit stains like stone fruits may benefit from rubbing with glycerine first.
Grass: Try soaking the item in full strength vinegar for half an hour before washing. If stains remain, try sponging the stain gently with rubbing alcohol before rewashing.
Grease and greasy stains: Cover fresh stains immediately with salt to blot up the excess oil. Brush off gently and dab any remaining stains with vinegar, or gently rub a small amount of dishwashing liquid into the stain. Wash as usual.
Marker pens: Try dabbing gently with methylated spirits, changing the cloth frequently to remove the marker. Wash as usual.
Mud: Allow to dry and brush off as much as possible (you can even try the vacuum cleaner nozzle). Rub liquid detergent into the remaining stain and allow to soak, rubbing occasionally, for 30 minutes, then wash as normal.
Paint: With water-based paints, try rubbing the mark with dishwashing liquid or dab the stain gently with methylated spirits. Rinse and wash as usual. For acrylic paints, dab with turpentine or gently apply rubbing alcohol with a toothbrush. Rinse thoroughly and wash as usual.
Rust and mildew: Make a paste of lemon juice and salt and apply to the stain. Leave to sit for 30 minutes - if the garment is white leave it in the sun (don't do this with coloured garments as it will bleach the fabric). Rinse and allow to dry (but not in a dryer). Repeat if necessary.
Soft drink/ soda: Treat as per fruit juice stains (most soft drink dyes are vegetable-based).
Tomatoes: Sunlight! Wash the item as normal, and then hang right-side out in the sun. Like many fruit stains, tomato stains are UV-sensitive and will fade to nothing with exposure to the sun. Many a bolognaise-stained white shirt has been saved this way at my house ;-)