You may not realize it, but you smell bad. How does this writer know this? She's a woman. Women spend their whole lives walking through Man Smell. Every mother we know can olfactorily mark the moment her son enters adolescence. They can immediately discern which towel you used, which pillow you slept on, which baseball cap you wore, all because the collective X-chromosome nose knows. And in the case of lavish cologne users, anyone can tell where you've been because, frankly, who can't? Now this is where you say, "But my girlfriend sleeps in my T-shirts because she says she loves my smell." So (a) you've been dating, what, six weeks? And (b) no, she does not love "your smell" – she loves your detergent, shower gel, or other subtle product she associates with you.

The irony is that most men are not naturally redolent. They're simply doing – or not doing – a number of things that cause reekage. So the next time you're in an elevator and notice women pulling hair over nose or plunging whole heads into their handbags, don't apologize for it. Fix it. Better yet, fix it without looking like you're trying too hard. Here's how.

Before you can get to Good, you have to achieve a baseline of Not Bad. Sweat itself doesn't smell, but "it creates a moist environment that breeds bacteria and fungus, which produce foul odors," says New York dermatologist Dr. Allan Izikson. The more protected the area, the fouler the odor – this is why your sweaty shins don't smell but your groin does. Izikson recommends showering before bed and using an antiperspirant with aluminum chloride, so you don't marinate in stink for eight hours. (Old stink is harder to eradicate than new stink, just like old stains are more difficult to remove than new stains.) You are what you bathe in. Avoid sweet floral scents – the idea is to smell like Enhanced You, not Aunt Jeanette. Try Thymes' Bergamot Vert [$13; thymes.com], and use a scented hand wash like C.O. Bigelow Orange & Coriander [$12; bigelowchemists.com]. Be sure to thoroughly dry your underarms and genitalia (and throw the towel in the hamper); you can also use an antifungal powder like Gold Bond to absorb moisture. Some deodorants smell like bad cologne; others don't last the day. Find a clean scent that fights the good fight, like Degree Invisible Stick Sport. No one has yet to make an effective, natural antiperspirant, so you'll need those chemicals to smell better. [$4; degreedeodorant.com]. If odor persists, says Izikson, try an antibacterial wash or shave your armpit hair. Also, a little known fact: Many men who sweat excessively get Botox injections under their arms to stem the flow. Truly. But, shhh, it's a secret.

Also, watch your head: Hair traps sweat, thus providing the perfect party spot for bacteria-induced odors. You know how a hairy dog smells after a walk in the rain? He's thinking the same about you. "Most men don't know it, but their hair and scalp smell odious," says Laurent DeLouya, owner of New York salon La Boite à Coupe. A man's hair should smell fresh, not perfumey. Be sure to lather up those especially funk-friendly spots like behind your ears and the nape of the neck. We like the delicious scent of Shu Uemura [$48; butterflystudiosalon.com] and Davines NaturalTech Purifying Shampoo [$25; davines.com]. To further ward off the stench, DeLouya suggests using a post-shampoo rinse of apple-cider vinegar and water, which will help neutralize the smell. You can also use lemon juice. "Men's hair is oilier than women's," says DeLouya, "so the lemon sucks out the grease – plus, it can help fight dandruff."

It may sound obvious, but – duh – stop rewearing your clothes, especially exercise stuff. "You must wash clothes and workout gear after each use," says Marshall Roy, a trainer at Equinox fitness clubs in New York. "Get out of them as soon as possible, shower, apply deodorant, and put on clean clothes – every minute you wait intensifies the funk." As you probably know from being at the gym, wicking athletic clothes smell worse than natural fabrics: Reduce fumes by soaking them in a cup of baking soda and water until you can wash them. A scented laundry detergent will also go a long way to curb the smell, since clothing is the first thing to absorb your noxious sweat.

Now that you've eliminated the negative, it's time to accentuate the positive. If you must wear cologne, go easy on it: A scent is a personal fragrance, not a room spray. For something subtle that won't overpower, try Malin + Goetz Tonics in Petitgrain or Lime. Both are infused with natural extracts instead of synthetic fragrance for a safer, subdued scent [$48 each; malinandgoetz.com].