Every Summer, it never fails: I buy the perfect white dress  or the crispest pair of white jeans , and the instant I set foot outside, it's as if all the stains found a new place to hang out. This year, I'd given up on the prospect of wearing my now-dingy whites — until I tried a few tricks (one of which involved a lemon and my fire escape) that actually managed to work.
If you've been determined to wear only the whitest of whites this season (and through Fall, because we all know the no-white-after-Labor-Day rule is a lie propagated by LBDs) but now they're looking a little dull, let this eight-step garment care guide brighten the way. And not every white tee in your closet needs the complete workup, so figure out what's doable for you. After all, no one wants to spend their final days of Summer at the laundromat.
Source: Le 21ème | Adam Katz Sinding 
Sort Your Laundry Pile
1. Sort by Color
Separating whites from colors might be one of those classic nuggets of wisdom every mom passes along to her college-bound child. Still, it can feel silly to have a heaping pile of laundry with just a handful of whites. But resist the temptation to merge.
Why? If you've ever seen a clothing tag with rather specific care instructions — "Turn Inside Out to Launder," "Use Cold Water," "Color May Wash Down," or "Wash Before Wear" — it's because those garments aren't colorfast, so their dye molecules wind up in the wash water only to settle on other fabrics. (Anyone who's ever accidentally put their new red towels in with their crisp white bed linens  knows what this means.)
2. Sort by Fabric
Color separation is Priority No. 1, but if you're a bit fanatical, you might consider separating them by fabric or level of dinginess. Linens and cottons can be washed together, and so can acetates and acrylics. Wash wool pieces on their own, and if your delicates should be washed by hand, just suck it up.
And if you are determined to whiten your heavily soiled socks, don't throw them in with your just-worn white tee — the dirt removed from one might end up on the other.
Don't Wait Long
Yes, we get it: You've got a measly "pile" of whites that consists of a tank top, a button-down, and a pair of denim jeans. As much as you might think it best to set these aside until you've gotten a few more pieces to add to the pile, it's not.
The longer you let those clothes sit before laundering, the more time once-invisible stains have to set. If you wait a month to wash that white button-down, for instance, by the time you throw it in the washing machine, it has very likely acquired yellow stains under the armpits from perspiration and deodorant that have taken hold of the fabric.
White-Hot Tip: Wash white pieces after every wear, even if they still look clean. We're all for rewearing jeans and sweaters, but your whites should be the exception.
Pretreat Problem Areas
1. How to Tackle Grease Stains
If you've got perspiration or other oil stains, pretreat them with liquid detergent, dishwashing liquid, or even clear shampoo. Don't rub in the liquid with your fingers if you can avoid it — instead, opt for a toothbrush.
2. How to Tackle Colored Stains
For anything that has left a color — whether it's a dribble of coffee, a splash of red wine, or a dollop of pasta sauce, and even those yellow deodorant stains — apply an undiluted oxygen-based bleach like OxiClean.
White-Hot Tip: If you've got time, soak the pretreated garment in hot water to loosen up the stain before throwing it in the wash.
Wash Your Whites
1. Don't Overload
A benefit to not having a ton of whites? You won't run the risk of overstuffing your washer. You need enough space for the detergent and water to work their magic.
2. Use Hot Water
The best way to retain whiteness is to wash items in the hottest water possible, at least 120 degrees.
3. Don't Scrimp on Detergent
Now is not the time to be conservative about how much detergent to measure. Use the maximum amount recommended for your whites.
4. Add a Whitening Boost
Baking soda or oxygen-based bleaches can increase the effectiveness of your wash. If you prefer a more natural route, a good alternative is lemons! Use a half-cup of fresh-squeezed lemon juice with your detergent to slightly whiten those whites.
White-Hot Tip: Steer clear of bleach. It's a common misconception that chlorine bleach is a cure-all for all your laundering woes. In fact, if used over time, it weakens the fibers in your clothes and, if you have water that's high in iron, can even cause yellowing.
Rinse and Repeat
If you take a wet garment out of the wash and see that it's still stained or dingy, do not even think about drying, unless you want the stain to set. Instead, repeat the washing process again. If it's an aggressive stain, consider applying ammonia directly to it, soaking it for 10 minutes, and then putting it back in the wash, by itself, for another go.
Dry Your Whites
For the most part, drying will set the fabric, so what you see is what you'll get. However, if you are able to air-dry your clothes outside, the ultraviolet rays of the sun act as a natural whitener. (This method works best if you used lemon juice in the washing process — just as putting lemon juice in your hair in the Summer can make you blonder, the same works for clothes!)
White-Hot Tip: Clotheslining your garments in the direct sunlight for a few hours should be enough, but to make them even whiter, feel free to put them back out for a few hours another day. Just don't leave them out for days at a time, as that can weaken the fabric.
Accept What You Cannot Whiten
You can surely keep your whites looking crisp, but after a few wears, they might never look fresh-from-the-store perfect, no matter how hard you try. White fabrics are typically treated with optical brightening chemicals that boost whiteness, but they eventually wash out over time.
White-Hot Tip: Annoyingly, storing whites in the dark can even cause yellowing, which is especially frustrating for those who do the seasonal closet switch. Storing items in acid-free tissues and nonplastic boxes can help.
And If All Else Fails . . .
You can always wear black.