(something like Dez 24 and January25)

First I printed the shape resulting from my CAD work an arranged it n a matrix board:

PCBs are made of a layer of different materials including fiberglass and resin matrix and some more. I have seen some people using a belt sander and alike to get boards in the desired. I do not recommend that unless you have a really good extraction system at your sander.

To reduce chips and dust going everywhere I used a fine saw blade on a Goldshmiths' saw. Those are usually work while pulling, I added some tape (sticky side up) right over the handle:

That way most of the particles do stick to that pieces of tape and can be folded in, once you are done sawing. This only works to some extent as the result show, but I did clean that up by sticking tape to it, too.

Not a quality cut, but I remember to have been a bit in a hurry (which you should never be for such work). Turns out I needed to adjust things anyway.

I did the same cutting the corner of the trinket (sorry Lady Ada!).