Run em into a curb or two. Use a prybar to mount/unmount the tires a few dozen times. Use a torch to cut off a lugnut, paint em, strip em, drive a few miles with a flat tire, drill em for moon discs, twice, use a socket 3 sizes too big on the lug nuts, strip the center cap screws or drill some and then strip them if they don't have them, have cats and dogs and an occasional drunk friend pee on them and then, use them as jack stands for a real heavy project car. That's a start anyhow.
Why make something look old? It like people buying jeans with holes and wore places... Just put them on and use them, than eventually you will have aged wheels... Its that simple...
A really good way to screw up a brand new "chrome" powdercoated wheels is to wash them with undiluted Purple Power.
I just read a tip in This Old House magazine about aging copper; Tom Silva was using a mixture of water and vinegar sprayed on to blend new copper into an old house. I would think spraying on would give you a more even surface than wiping or rubbing.