I recently got Plexi Class - a book about creating plexiglas jewelry. Well, I have a plastic cutter already and some plexiglass. I have sheets of it. They are about 1/8" thick or about 3 mm. Do not get it too thin or it might be too sharp to wear unless you use more than one layer. Thin might be okay for earrings. You will see in the pict that I did some simple ones. I will play more later when I am not so tired and don't have a killer migraine. I have not had one of these since before my sinus surgery. I hope that this migraine is more the exception than the rule.
Cutting plexiglas is a lot like cutting glass or tile. You need to have a plastic scorer. I have a scorer like the one in the book. It is the Fletcher brand. I recommend that you put something underneath your cutting mat to catch the little bits of plexiglas that comes off when you score it. BTW, The tool is very sharp and it really digs into the mat. You might want to use one that you don't care if you have gauges in it. Do as the book says and score the plexiglas at least 5 times to get a deep groove. I used a towel and put it over the piece I was taking off the larger sheet. It gets easy to break off the pieces once you do it a few times. There is also a tool that does it. It looks like a wide mouth pliers that has a rectangular grip. I don't have one of those and don't need to have one. BTW, the little bits and shards are very similar to glass. You can hurt your feet if you step on one. I got a little plexi sliver in my hand and had to dig that out. Just warning you, if you want to play with this. I vaccuumed the area where I was working after I was done so my kids would not accidentally step on anything sharp. I cut several smaller pieces from the large sheet.
First, I tried to smooth out the edges with the grinding attachment on my Dremel. It ended up melting part of the edge. No matter what the speed, it melted part of my edge. I tried it also with the fine sanding attachment and it did not give me a smooth edge. I ended up using fine grit sandpaper. You might want to use a sanding block if you have any problems with your hands. Do this in an area that you can easily clean up or over a big garbage can. The fine grit sandpaper also was able to round out my corners a bit. I got nice, rounded corners. I sanded the surface of the plexiglas piece to get that frosted look.
I tried one piece where I layered it and joined the two pieces with small 1/16 screws and nuts. That was okay. I liked the embossing better. I am going to try it with a hole through the plexiglas and wire wrapping small objects in the hole. Lots to try, but when I am more coherent. I think I might do this for my charm necklace swap. I plan on finishing these plexi chams - turning them into necklaces/chokers. I will post when I do that. Trying to get some sleep now. Big day later on today. Bead show and then meeting up with some fab artists.