I decided to try to make shot glasses out of ice slabs made in a cooler. I froze water, cut it into big cubes and then bought a 1.5 inch drill bit.
I was surprised to find how easy it was after that. I drilled a hole in the middle of each. Then, knowing that with the huge amount of room outside the hole it would be impossible to actually drink a shot out of them without spilling it everywhere, I decided to chop off some of the side of each cube with a big knife.
Oddly, though I've been making shapes with ice blocks for a decade, I don't think I've ever tried to carve it with a knife. Turns out it's super easy.
So these will make shot glasses and/or votive candle holders.