Some women would rather give up sleep than go without their nightly cleansing, scrubbing, toning, and moisturizing routine.

For many women, the actual therapeutic value of the routine is beside the point. As one friend told me, "Once a week, I like to pretend I'm in my own little spa. I soak my feet, put cucumber slices on my eyes, and feel like Lucille Ball." But whatever regimen is chosen, dentists, podiatrists, and dermatologists are generally in agreement about what's necessary and what's merely window dressing.

Under "necessary," there's "brushing, flossing, flossing, and flossing," says New York cosmetic dentist Marc Lowenberg. "Did I mention flossing?" Plaque and bacteria start to harm teeth and gums after 24 hours, so they must be removed thoroughly at night. "Most people go to bed with food debris in their teeth," he adds. "That gives bacteria a head start."

For foot care, remember: Those feet were made for walkin'—which is why podiatrists emphatically caution against rubbing away calluses with pumice stones. "I hate those things," says Richard Kushner, a New York podiatrist. "This is how people get fungal infections. The ideal nighttime foot care is a little rubbed-in moisturizer." Otherwise, he says, "leave your feet alone."