I got really bored last summer and looked up how to cut glass. You can do it with string, rubbing alcohol, a lighter, and bucket of water. I had a bunch of cool cobalt blue bottles (from my favorite energy drink) and I turned it into a little hiding pyramid for my fish. It was easy, and entertaining. I sanded down the cut edges so the fish wouldn’t hurt themselves.
I also have a broken Japanese bowl that was too pretty to just throw away; my fish seem to like it also. Its one of their favorite hiding places. There is also a broken coffee mug and broken pieces of a flower pot silicone together.
OH, and a plastic triceratops and a little plastic tree my roommate got at a dollar store, Cheep plastic kids toys rock!