IN GENERAL
Treat stains ASAP. The longer you wait, the harder it will be to get rid of. Avoid tumble-drying or ironing before cleaning as the heat sets the stains.
Choose the right water temperature. Choosing the wrong one can actually set stains. Use WARM water for oily/fatty stains; COLD water for all other stains (ex. coffee, blood, chocolate, ketchup, red wine).
Use gentle detergents. NO bleach or harsh stain removers, which only strip and damage the fabric. If unsure, spot test in a small spot or the storage bag. Dab or gently rub; don't scrub.
DIY stain remover: Soak stained areas in 1 part vinegar + 4 parts water for a few minutes and launder as usual.
If treating with detergent/vinegar solution is not enough, repeat a few times. For severe stains, it’s good to err on the side of caution and take it to a cleaner.
COMMON STAINS
Oils (natural body oils, lotions, food). Spot clean with mild dishwashing liquid, a natural de-greaser. Wet stain with lukewarm/warm water, gently rub with dish soap and launder as usual.
Blood. Fresh/wet blood: rinse immediately with a blast of cold water so it doesn't set. Gently rub with soap and rinse with cold water. Dried blood: apply thick paste of salt + cold water onto stain and let soak 10-20 minutes. Gently rub and rinse with cold water.