We get the rivets at work via LPKF. Basically, you have to drill the correct hole size and have sufficient pad size for a given rivet size.
eg 0.9mm hole and 1.5mm pad size. Then you poke the rivet through the hole (best to do half a dozen at a time) and then you use an impact tool (provided by LPKF) to 'click' the rivet into shape.
The impact tool looks like a metal screwdriver but it has an internally loaded spring so when you press down on it, it gives out a large click and forces the rivet into place. It's a noisy and slow process but the results are good. Also, the holes are hollow just like a plated hole so you can fit leaded parts if you wish. (can be useful for connectors)
I'd hate to do a board with lots of ground holes LOL.
This looks like it below although I think the one I use is an older model.
**broken link removed**
Boards milled and riveted and then tin plated can look pretty good
I use this stuff for tin plating. It doesn't need a hot tank and it doesn't smell etc.
When mixed up it looks like cloudy white water and it can tin a PCB in a few minutes.
MEGA|600-020|TIN PLATING POWDER 90G FOR 1 LITRE | Farnell United Kingdom
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There are other techniques, eg using ferric chloride to etch PCBs and this can work well. Especially if you are doing RF designs with basic signal paths.
Otherwise, at 2GHz the PCB construction could be done by scalpelling out very basic signal paths on a bare board, but this is hard work...