Jewelry Saw
Sometimes I modify the bits and pieces I use in the keys. Here's a piece of bracelet that I only wanted half of so I got out my jewelry saw:
Of course I broke the blade (it's been awhile since I've used a saw). But that's OK.
Eventually I had success!
After sawing the pieces apart I used a fat bastard file (yes, that's what it's called) to smooth out the sawed edges.
I glued this piece onto the end of a key in progress and left it to dry for the night.