Yay! I have to do laundry less now after reading this!!!!

Bras
How often you should wash them: After 3 to 4 wears.
What to know: Bras don’t come into direct contact with the   underarms, so they can withstand a few wearings. But they need a 24-hour break   between wears for the elastic to recover, so try a rotation system: Line them   up in a drawer. In the a.m., take a bra from the front, then send it to the   back of the line in the p.m.
  Exception to the rule: Sweat a lot? Then wash bras daily with a gentle baby   detergent, like Dreft. Perspiration wears down the elastic, so keeping a bra   clean will increase its life span.

Jeans
  How often you should wash them: After 4 to 5 wears.
  What to know: Durable denim is excellent at masking dirt—which is a good   thing, since overwashing can cause jeans to fade and fray. To keep yours looking   like new (or “weathered” just the way you want them): Throw them in   the washer inside out and use cold water. Avoiding the dryer will help retain   color, too.
  Exception to the rule: Take them for a spin cycle sooner if they stretch out.   Or just toss them in the dryer for 10 minutes (but no more than that). Spandex-heavy   “jeggings” (jean leggings) should be washed after every wear so the   knees don’t bag.

Dress Pants
  How often you should wash them: After 4 to 5 wears.
  What to know: You’re probably wearing these in an (overly) air-conditioned   office, so feel free to revisit them multiple times, particularly those made   of stain-repelling synthetic blends. Part of a suit? Dry-clean both pieces together   so one doesn’t fade faster than the other.
  Exception to the rule: Your nice trousers will last longer between washings   if you change into your “play clothes” as soon as you leave work (as   opposed to wearing them to your daughter’s soccer game).

Jackets and Blazers
  How often you should wash them: After 5 to 6 wears.
  What to know: Typically layered over a blouse, a tee, or a camisole, these don’t   require much upkeep. However, a jacket can retain odors (say, from last night’s   fajitas), so before you stuff it in a closet, air it out near a window or spritz   it with the Laundress Fabric Fresh ($16 for eight ounces, thelaundress.com).  
  Exception to the rule: Periodically check the high-friction areas—collar,   cuffs, and placket—for signs of dirt. But you can roll up the sleeves (or   even pop the collar) temporarily to conceal stains on an otherwise-clean jacket.

Khaki Shorts and Pants
  How often you should wash them: After 2 to 3 wears.
  What to know: Light-colored cottons are vulnerable to noticeable spots. Zap   smudges between washes with Oxi Clean Spray-A-Way Instant Stain Remover ($3.50   at drugstores),
  Exception to the rule: With stain-resistant fabrics, you can get away with an   extra wear or two. Never use fabric softeners or dryer sheets, as they diminish   the effectiveness of the fabric.

Pajamas
How often you should wash them: After 3 to 4 wears.
What to know: Swap out your pj’s twice as often as you change the   sheets. People don’t realize how much they sweat at night and we also shed   thousands of skin cells a minute.
  Exception to the rule: Do you shower before bedtime? If the answer is yes, you   can sneak in an extra wear or two. However, if you snooze in silk, which absorbs   more body oils than cotton, you should switch up your sleepwear daily.

Skirts
  How often you should wash them: After 4 to 5 wears.
  What to know: Chances are you’re not doing anything strenuous in skirts,   so you can wear them multiple times. Just refresh nonsilk fabrics with a 10-minute   spin in the dryer with a dryer sheet.
  Exception to the rule: You can be more lenient with circle and A-line styles,   which hardly skim the body. But “whites and silks are prone to discoloration   and should be cleaned after every wear.

Swimsuits
  How often you should wash them: After every wear.
  What to know: Salt and chlorine will eat away at a swimsuit and stretch it out   prematurely. Hand wash your suit with cool water and a gentle detergent, like   Soak ($10 for four ounces, soakwash.com), which deep-cleans and removes that   notorious chlorine smell. Allow the suit to air-dry.
  Exception to the rule: None. Even if you only dipped a toe in the water, a swimsuit,   like underwear, is an intimate garment that absorbs body oils, bacteria, and   odors. Best to wash it every time.