I made a candle holder out of a skull-candy mold. Don't ask me who's making huge-ass baseball sized skull candy, but it works just as well with plaster, would probably work with cement or candle-wax or whatever...
Mold: $1.49 at a hobby shop
Plaster of Paris: $7.00 (makes 6 of these doo-dads!)
Then you can use paint to tint them... or paint them when they're done.
Mix plaster, pour the mold half full then tap gently on the work surface to bring bubbles to the surface.
Fill the rest of the mold.
Next day, mix a little plaster or use some joint compound to glue the two sides together... Smooth around the seems with more compound and a little water.
Then let it dry, sand lightly and paint.
If you want to make it a candle holder, i'd seal it with something more substantial--like epoxy, and of course you'll
have to drill a hole in it. Best of luck.