As many have noted, SL residents seem to come in two flavors. Some folks think of their avatars as people think of clothing: something to select based on where one is going, or even one's whim.
I'm of the other sort. My avatar is me, in SL at least. I had some fun being a she-raccoon once, but I mostly take changes to my avatar very seriously, almost as if I were contemplating cosmetic surgery.
I knew most of what I wanted from the beginning: I love red hair, so I wanted it. Ditto for green eyes; long ago, a beautiful woman with eyes the exact color of Palmolive dishwashing soap was a coworker, and I never forgot those eyes... so I jumped at the chance to have them. Ditto for a long, slender neck, and impossibly long legs (so much so that despite wanting to be as tall as possible, I held back on torso length to keep the emphasis on the legs). Pale skin goes with red hair, of course, so there you go.
Breasts? [nods sheepishly] Yes, I ran the slider all the way up, biting the bullet of bad rendering at the extremes. (If this bothers you, too, I hope you'll take a look at Proposition 125, proposed and cogently argued by Snakekiss Noir.)
I mostly like the results, though when I see my unclad or less-clad SL self, I think I look like a scarecrow and wonder about being a bit more zaftig. (See what I wrote? Not "that avatar with little or no clothing," but "my unclad or less-clad SL self." I didn't think about how to write that; that's just how it came out, and it shows how attached I am to my avatar. Fans of Bertrand Russell's theory of descriptions will point out that just writing "my avatar" like that folds in an assertion that there's only one.)
Along the way I found a skin titled "Vanilla Rose," put it on, and liked it a lot... and more importantly, didn't care too much for the other skins I tried, until I read Celebrity Trollop's inaugural Celebrity Couture Culture column, "Navel Gazing." More accurately, until I saw that first picture!
Now I am looking for a skin with those "digital abs of steel," to use Wagner James Au's felicitous phrase. [Correction: to use Celebrity Trollop's phrase, as Mr. Au did!] Of course, I also want to keep the skin and lip color I like from Vanilla Rose... and now I think I can, thanks to this entry in Ms. Trollop's Second Style Fashionista blog. It's close enough to my current skin and lip color, and has the detail I'm looking for. Ms. Trollop helpfully mentions the skin in the video... so next time I'm online, off I will head for Naughty Designs. Thank you, Ms. Trollop... I have my fingers crossed.