I just thought it was worth pointing out that unless you're shooting glamor photos, not everybody wants an artificially flawless picture of themselves...
Retouching a portrait doesn't have to go to the "artificially flawless" level, but I've yet to have a portrait subject who didn't want stray hairs nuked, a few wrinkles lessened, eyebrows worked a bit, a blemish or mole removed or lessened, neck shrunk a bit, clothes dewrinkled, a gray hair nuked, etc.
I've had to de-red-eye models who drank too much the night before a shoot- show me a female who wants to get her picture taken without make-up and her hair done, and then we can talk about natural- but I've yet to encounter that scenario, so I'm assuming it's not all that common, especially with older subjects.
A portrait is a visual representation of the client, not a news documentary shot- so a "quality" portrait represents the client in their best light- and if you present the client as they really look, you'll often not get them back- even the ones who profess to want a natural look are more vain than they think. A quality landscape has great looking scenery with great lighting, and a quality portrait has a great-looking subject with great lighting. You can go for "gritty" with some male subjects- but side-light a woman at your own peril.[1] Just like you wouldn't short light a skinny person or broad light a fat one and expect quality results, leaving all the flaws in- especially in these days of high-resolution lenses and cameras is a mistake. Soft focus lenses, pantyhose over the lens, and all the other tricks of the portraiturist are time-honored traditions because they produce the looks that people generally *want* in their portraits, reality not withstanding.
Paul
[1] I'm all for equality, and I think women shouldn't have to feel it necessary to don makeup at all, let alone spend two hours on their hair before going out, but society seems to be less even-handed than I'd like and most women seem to be attuned to the social dance and apparently that picture _making_ them look "old, fat or bad" is more at fault than reality in many of their eyes. Then again, I retouch some self-portraits, so I'm not immune to vanity either!