As you would imagine from looking at some of my Drabbles series of portraits, I have no problem with a lot of post-production. But that's mostly when I'm trying to create an image that is almost an illustration, as much as it's real portrait.
But for the most part I tend toward the middle of the road when it comes to retouching, but will admit that this has changed over time. I went from very little, to poorly executed, to fairly well executed but way too much, and then back down to where I am now, which is hopefully very well executed and largely subtle.
As an example, here's a shot that I took of my friend Caroline the other day. You may remember her from the Drabble of the girl running down thestairs in a blue dress (link)
One light in a softbox high and to the right and fairly close. While she is obviously a very pretty girl and certainly doesn't need a lot of help from me, I thought I'd show you a before and after so you can see where I came from and where I went. Hopefully, it's somewhat polished without looking too fake. The trick is to not make it too perfect, unless of course you're doing a make-up advertisement in which case you might as well just Gaussian blur her skin to within an inch of it's death.
By the way, before some of you accuse me of trickery, all of the blur in the photo (torso, hair) was done in camera. I was shooting at f/1.2