I have figured out a great way to make 'random' sims, without actually hitting the randomize button, which can result in some pretty freaky looking sims. My biggest problem was I kept making the same sim over and over. I liked certain features and inevitably all my sims would end up looking the same.
Basically I have a collection of sims I've made over time, and also sims I've downloaded/gotten from other people. If I run across an interesting sim in game I use the cheat to bring them to edit and make a copy of them in the bin.
Then, whenever I am creating a new family, I just pick two random sims from the bin and use the built in genetics to generate children from the two sims I picked. Once I have a kid I like, I delete the parents. Because they aren't actually genetically related this has no effect on the sims/relationships in the actual game.
This results in genetically variable sims that are still usually to my liking! I can then take the generated child and put it at any stage of life and change the clothes/traits/wishes to my hearts desire. This helps me be more creative and still get sims I like to look at, without having to do quite so much sifting through and modifying of the randomly generated sims.
This is doubly good because you can also download one of Twallan's mods which will cause all sims that move to your town to be randomly generated from the sims in your sim bin, instead of getting the same vanilla face everyone hates.