...man. It's really surprising how a) understanding your tools and b) having better tools can result in improved results with Sim creation. Almost universally, my old Sims look like shit warmed over, but when I open them up in Body Shop and tinker with them, modifying custom skintones and hairs and clothes and makeup and eyes and everything else, and subtly correcting their awkward, 2004-era features, the effect is kind of startling to me.
Most of them aren't actually all that fugly inside! The intentions were good, but the execution was sloppy.
Consider poor old Suzie Chambers, one of my very first custom Sims, and considerably less-poor new Suzie Chambers:

Not half-bad, by my standards. You can only sort of tell they're the same Sim, even though I treated her genetics like a broken-down heritage house and tried to only fix what was legitimately borked. (I'm doing the same thing with the dudes. It's just easier for me to tell the difference with the women, because... well, you know.)
Not a lot of games that still work where you can actually benefit from your own nostalgia like this.
P.S. Her hair was originally red. I don't know why I changed it to that hideous beige mop. I only mention this so you don't think I'm going back and turning all of my Sims into redheads; I only mention that because it's totally something you could fairly think I might be doing.