Skills of the sims

creating a twin is a great way. 🙂

You can use the genetics option in CAS to create a twin sibling of your Sim. You'll have to manually set their hairstyles and outfits, etc., to get those to match. 

I use the MCCC mod to copy/paste things like face shape, body shape, physique, etc., if I want a fast way to create a clone of any Sim. I can use the same mod to copy/paste hairstyles, outfits, accessories. MCCC also has options to cheat skill levels up or down, including setting them back to 1.