I'm posting some links to some helpful tutorials -- because I think I might need them later and be unable to find them in my humongous Bookmarks folder!
A tutorial on how to change an adult Sim's gender!
A combination of SimSurgery and BodyShop to tidy up the mismatched clothes and such...
Warning: Gay Sims Club 2 is for persons over 18 only.
Giving your in-game sims a permanent make-over by Wirelessguy
A similar tutorial on a non-adult site.
UV Map Tutorial
The version for Custom Meshes allows you to extract a mesh and view its UV Map. The UV Map can then be used as a layer in a PhotoShop file to help skin or recolor a mesh.
Note: The newest version of UVMapper won't save the UV maps because they want people to buy their proggie. If you click on the UV map and press Ctrl-A to select the entire map, you can Copy it and paste it into your favorite paint proggie.
Gothplague's UV Map Tutorial
Zirconia Wolf's Tutorial to Make Skintones Use the Adult Mesh For Elders
Tired of droopy boobs and saddlebag thighs? Upgrade your favorite skintones to use the adult meshes for elders!
Making Your Own Clothing Hiders/Unhiders/Recatagorizers
Zirconia Wolf's Version
Phaenoh's Version
Maxis BlockFoot meshes to fix your ruined outfits
Tutorial is on the last page, or you can use Gothplague's tutorial and these meshes. Also helps fix bare-toed XHi-Res Warlokk meshes.
Fixing Blue Flashing Accessories
Inge's method for how to move the produce of puppy-kitten mills to other 'hoods which is also a sensible way to deal with the zillions of Maxis produced strays!