Some of them only take 5 minutes especially if I am editing a random townie. Other sims that are part of my main playable group may take longer. In particular, more widely played sims will have multiple sets of outfits per type which can take longer. Sometimes lately I've been using the styled looks to speed things up but must of the time, I put together individual outfits, make up for female sims, etc.
I'm usually on the faster side now. I tend to randomize until I find a sim I either want to keep as-is or edit further. I usually make some minor changes for whatever look seems to suit that sim. Sometimes I edit the walk style. It's rarer now that I change the voice. Picking traits does not take me that long.
Sometimes I'll start a sim out and then go back into CAS later to add more outfits. The only "plastic surgery" I do is reducing the fat on sims if it seems that they've gotten unreasonably fat in a way that doesn't make sense. I've had this with a few sims.
I try to just make interesting sims. Often my goal for their look is for it to look good, to suit their personality as I've developed it and for them to look different from the others. When deciding on a random sim to work with I kind of view it as casting them into my game and I'll say, "Oh, that's a cool looking sim who is different from the rest in my game." Sometimes I then want to edit them to fit whatever general idea I had in my head.
