I came across this article a while back, outlining a technique for making shim washers. I posted the results of its use on my airgun blog but figured it would also have applications in jewelry making that might interest some people.
Some copper sheet is placed in a disc cutting die (this is actually a shim punching die, but there is no difference)
A transfer punch (this one's a nice Oldak, but any type will work) punches a divot in the center.
It's important that you not shift the stock at all...
The OD (outside diameter) of the washer is punched out, I use an arbor press instead of hammering.
I then insert the disc in the die again, and align it to the ID (inside diameter) hole with another transfer punch. Then you punch out the ID just as you did the OD
This is a set of fractional transfer punches.
The washer...the hole was within about .004" of center, which is pretty good!