First, rub an even layer of wax over the paper. Since this is for a miniature and my block of beeswax is rather large, this is fairly easy. (This fantastic block of beeswax, by the way, was found in a local health food store for less than $3.)
I then experimented with different ways of sanding the waxed paper. Regular fine grit paper did not work--it rubbed off some of the ink. I found this rubber sanding pad at the hardware store, and it works well. I can also roll it up to make it a little easier to grasp. For some reason, a regular sanding block with the same grit number did not work.
Then smooth with a buffing pad, also from the hardware store.
Wiping with tack cloth helps smooth out the wax, but it can leave a little stickiness. I buff some more after this step. Repeat until the desired finish is obtained.
Even though this is a small area to do, this process was causing me problems. I have painful and not very strong hands. I got the idea to try a cheap electric toothbrush to do some of the buffing. It works...up to a point, although I found it actually was not that much easier. However, it is another option and does allow for some finer finishing. I discovered at the drugstore that the toothbrushes are not all equal. Some only vibrate, and others simply don't feel nice in the hand when they're turned on, and, on some, only a small portion of the head moves. If you like this idea, take advantage of the ones that allow you to turn them on in the package at the store. That way, you can get a better idea if it might work for you.
In spite of the hand thing, I've been excited about this. The finish is just perfect for this project. It's smooth and glossy, and is far more durable than regular unfinished inkjet paper. It also deepens the colors of the printouts. I use an Epson with pigmented Dura-Brite inks. I'm not sure how others would hold up to this process, but I imagine they'd be similar.