Cutting Thin Sheet Metal?

Google xuron cutters

or: get a small mirror tile, put sheet on mirror tile, cover part with sellotape or other branded clear sticky tape to prevent parts pinging off, & use sharp x-acto or similar to part it from sheet.

a small diamond file or similar will remove stubs.

I use a couple of different ways to cut them, but still get burrs and such where the cut was. I touch up that spot with a needle file.

BTW, I have one of those MM kits too.  I have used it for a couple of scratch models, but it sure is a lot of work.  I also have a set of toner transfer paper that is supposed to make PE parts, but the quality is nowhere near what you get with the actual photo process like the MM kit.  Toner transfer PE okay for larger parts, photo process seems to be only way for really small parts, though.

Paper cutter. Pick yourself up a paper cutter at the office supply store. These work much like a metal shear that is use to cut huge sheets of metal. You can also use them for cutting sheet styrene down too.

I found scissors will work well too.I use the Xuron cutter though as it works very well and does not compromise the part or send it into orbit. Shearing sheet is the best cutting action as opposed to 'separating' .