One surefire way to avoid sweat stains is to prevent them from happening in the first place. Knowing the causes makes a major difference; most stains are caused by a reaction between the salt in your sweat and the ingredients in your chosen deodorant, which usually has a high aluminum content. Over time, this aluminum accumulates on your clothing, leaving the yellowing stains you want so badly to avoid. Switching to aluminum-free deodorant could be all it takes to eliminate perspiration spots, especially if you wear shirts multiple times before washing.

Since sweat stains are partly caused by deodorant build-up, letting it dry before dressing could greatly reduce accumulation. Without that pesky rub-off, your chances of staining are much slighter, and all it takes is a few minutes each morning. In a rush? Move your armpit area over a fan or blast with a hairdryer (on the cool setting, of course) to speed up drying time.

Stressed about perspiration spots? Keep key supplies near your washing machine. The next time you come home after a long day, quickly jump-start stain removal with a bar of laundry soap. Scrub the spots immediately before tossing clothing into the machine, and you'll kickstart the removal process before the fabric even gets wet. It's also helpful to have an on-the-go stain removal pen handy when you're out and about, so you can dab any discoloration as soon as you notice it.

A key step in removing stains is soaking them thoroughly, so do this as soon as you're able; the sooner, the better. After dabbing with laundry soap, soak fabrics in a mixture of cold water and white vinegar, using equal parts of each. Let them sit for an hour or two, then wash on the cold cycle. If you're not noticing any difference, let them soak longer, wash, and repeat. The earlier and more thoroughly you soak stains, the easier they are to remove.

Speaking of white vinegar, boost the effects of the latter by keeping white vinegar handy and ready to use. You can use this ingredient in a scrub format or a spray bottle, so choose whichever method works best for you. This kitchens staple is a helpful aid in both the soaking and washing process, and soaking sweat stains in white distilled vinegar is an ideal way to foster its fighting power. Let the vinegar sit for 15 minutes prior to washing.

Baking soda enhances laundry detergent's cleaning power, so add half a cup each time you wash. This key ingredient works by drawing out stains and trapping them away from your clothing, balancing pH levels, and eliminating that dreaded yellow tint for which perspiration spots are so well known — and well-hated. A bonus? It absorbs excess odors that cling to fabrics, leaving them with a fresher scent and feel, post-wash.

This paste, much-loved by cleaning professionals, involves mixing many of the above ingredients into a thick layer that can thoroughly coat any yellowed, stubborn stains. Make the paste at home using 1/2 cup baking soda, one tablespoon hydrogen peroxide, and one tablespoon salt. Use a toothbrush to apply this paste onto clothing, let sit for an hour, then wash on the cold cycle. The longer you let the paste sit, the more it can work its magic.

The fighting power of Dawn does not go unnoticed, with this magic ingredient overpowering nearly any stain. Sweat spots are no exception, so if the above solutions haven't done the trick yet, it's due time to bring out the Dawn. The insider trick? Mix one part Dawn, two parts hydrogen peroxide, and a dash of baking soda to fully engage its removal power. Let your clothing sit in this mixture for an hour or two, then wash.

Sprinkle a dash of unflavored meat tenderizer over stains after washing, then re-wash again on the cold cycle. How does this work? Meat tenderizer is used to break down proteins in meat, and it can work to break down the same proteins in stains, making them easier to remove. When you've tried everything, this quick,if a bit weird, step can aid stain removal during the soak/wash/repeat process.

Paired with baking soda, ammonia makes a powerful stain remover that can finally wipe out those pesky underarm splotches. You'll need to combine it with oxygen bleach to engage its effects — steer clear of chlorine bleach, which can result in dangerous fumes. Even with oxygen bleach, avoid inhaling and create your mixture in a ventilated room. Three to four tablespoons is a standard amount for a couple of items, depending on stain size. Rub this mixture onto fabrics using a toothbrush, then let it work its way into the clothing for about 15 minutes. After soaking, wash with your usual laundry detergent, then hang dry.