I'm not sure whether you are asking about crotch sweat or vaginal odours here, so I'll write about both.
A healthy vagina has a musky smell -- this is perfectly normal! However it should not smelly rotten or fishy -- in this case you might have an infection in light cases a probiotic supplement might help, but if you feel a lot of discomfort you should definitely see a doctor.
I already wrote about how internal cleaning is harmful, however the vulva (external bits) should be cleaned thoroughly, usually twice a day. A pH-neutral cleanser is best, however a mild (SLS-free) soap is fine too. It's best to avoid any products with fragrance.
On to the crotch now. The groin area has apocrine sweat glands (the same type as the armpits), which smells pungent when decomposed by bacteria. So it might be the culprit if things aren't exactly smelling fresh.
Exfoliating the area regularly is the best way to keep things smelling fresh. Dead skin that has not yet shed can trap sweat and bacteria. An exfoliating glove or brush is usually better than a scrub. Gently scour the outer vulva, butt, and especially the crease where the thighs are connected to the torso.
A light dusting of powder soaks up any moisture.
To keep the air circulation going, cotton underwear is best, especially if you are going for more coverage. Avoid trousers out of synthetic materials that don't allow for air circulation.
Finally, water and soap will clean things a hundred times better than toilet paper will. I mean, would you be satisfied with cleaning your hands with only dry paper? There are many ways of going the water route, but bidet attachments are cheap and can be installed easily (without professional help) on most toilets.
If you haven't tried a menstrual cup yet, the lack of smell is another good reason to take the plunge. In short the blood doesn't get into contact with oxygen, so there is no smell.
Finally, remember that we aren't flower bouquets, it is biologically impossible to smell like one all the time. Especially at the end of a well-lived day. While it's a good idea to keep baby wipes around to freshen up at the end of such a the day, there is no need to get paranoid about normal body scents. While you might be attuned to your own smell, chances are nobody else around you can smell anything at all.
Do you have any favourite ways of dealing with such issues? Let me know!
Photo credit: Viliman Viliman