In my never-ending (and silly) quest to build everything myself from found items, here's a quick tutorial on making your own nuts and bridges from plastic dominos.
I read somewhere that really old dominos were sometimes made from bone, so I hit all the local flea markets and thrift stores, but no joy. So, during one of my daily visits to the World's Largest Retailer, I bought a $5 tin of standard plastic dominos.
I don't know exactly what these are made of, but it's not your typical cheap plastic. This stuff is HARD. In fact, short of a power tool, hand-sawing these things was a chore. Dovetail saw worked nicely, though.
These would both become nuts, so now the dots must go. I recommend a power tool here, but I guess you could sand them by hand. The dust is really fine - a lot like the bone they'll replace. If you sand them just barely clean, you'll end up with a blank that's a hair under 1/4 inch, which is just about perfect for a guitar nut.
A little more creative sanding, and you have something that looks exactly like a guitar nut - because it is! Trim the width as needed, file and sand, file and sand. A little steel wool evens out the sanding marks. I haven't polished any of mine, but I'm sure you could if you like a glossy look.
You can also laminate a domino on a piece of hardwood to cut into bridges. I've used wood glue for mine and, so far, no failures. I'm sure epoxy would work too, maybe even CA glue. Can't say, but I love the look of a laminated bridge. I think they dress things up a bit and it's really not much more trouble than a wood bridge.