At its most basic, a good beauty treatment should be three things: leisurely, not rushed or frenzied; pampering (what's the point, otherwise?); and as pain-free as possible. But beyond that, it can be hard to tell -- especially if you're trying something new -- what is and isn't supposed to happen. Are bright-red eyelids normal immediately after brow shaping? Are post-shave ingrown hairs simply unavoidable? How long is a manicure supposed to last? Here's what you should expect from four common spa treatments.

Eyebrow Shaping. Brow styling is extremely subjective -- one woman's glamorous arch is another's Betty Boop nightmare -- but some general rules apply. Aestheticians should "always work with the natural shape," says Maryam Gouloubandi of the Skin Savvy Spa Express (202-319-1231). "Otherwise, the brows don't match the face." For the best results, a combination of techniques is necessary. For example, Gouloubandi waxes or threads the fine hairs above and below the brow line, does the precision work (the arch) with tweezers and a magnifying glass, then finishes with a scissors trim. If necessary, aloe vera, ice or lotion should be used to soothe the skin afterward.

Red flags: Asymmetrical brows (no two are identical, but they should be "as close as possible"); stray hairs; bumps or excessive redness. Regrowth after less than two weeks means the hair was broken off, not removed completely.

Hot Lather Shave. Time -- as in, the more, the better -- is of the essence when it comes to this former barbershop staple. "You don't want to be crunched when you're taking a blade to someone's face," says Mike Gilman, co-founder of the male-focused Grooming Lounge (202-466-8900). According to him, a good shave includes four key steps: a prep with lotion and warm towels to soften the skin and lift the hair; application of hot shaving cream and shaving oil to create a smooth, anti-nick barrier; use of a triple-blade razor ("It's better than a straight-edge," he says) both with and against the direction of growth; and ice-cold towels to close the pores and refresh the skin afterward.

Red flags: Shaving brushes ("Not sanitary," Gilman says); nicks; breakouts; redness; regrowth a few hours after the shave.

Manicure/Pedicure. Cleanliness is king here. "The implements should be soaking in a sanitizing solution, and the nail technician should always wash your hands or feet or use a sanitizer before getting started," says Tonia Briscoe, the treatment director at Nusta Spa (202-530-5700). After that, expect a gentle shaping by filing in one direction (no sawing back and forth!), which prevents the nail tip from peeling; a warm-water soak to soften the cuticles, which are then pushed back ("Only loose skin should be trimmed," warns Briscoe, as "cutting the cuticle all the way back leaves you open to infection"); a hand or foot massage; removal of oil from the nail plate so that the polish can adhere; and four coats of polish -- one base coat, two color, one top.

Red flags: Over-aggressive filing; use of Credo blades (which are illegal in most states and the District); bleeding or peeling cuticles; bubbles in the polish (it was either too old or applied too thickly); polish on cuticles (which will cause the polish to peel after one or two days). Under normal wear and tear, polish shouldn't peel or chip after less than five days (if it does, the nail plate was probably not clean and dry enough).

Waxing. Because removing hair opens the follicles, a prime breeding ground for bacteria, no matter what's being waxed -- lip, legs, back, etc. -- the skin should first be thoroughly cleaned and disinfected. Wax should then be applied in the direction of hair growth and removed swiftly in the opposite way. Pain is probably unavoidable, but to lessen it, form is everything. "The hand should stay parallel and close to the body," says Azan Hedayatpour, an aesthetician at the Georgetown Aveda Lifestyle Salon & Spa (202-965-1325). After wax residue has been cleaned off, a soothing lotion should be applied.

Red flags: An aesthetician who doesn't ask you about medications you're taking or your skin-care routine (Retin-A or Accutane users, for example, have thinner, more injury-prone skin) or doesn't tweeze stray hairs post-wax; any pre-wax lotion application (it makes hair harder to grab); regrowth after less than two weeks.

Jennifer James

Foul! Shaving brushes are one of the no-nos of getting a professional shave. Bad, barbershop man. Bad, bad, bad.