The Glass & Concrete Candle seemed like a good choice for an existing design that I could simplify for sale on Etsy. (It can be purchased here.) I'd noticed that although the height of the candle looked cool, that the capillary action that fuels the flame wouldn't work once the oil level was more than a few inches below it, so I bought some glass vases that were shallow.
Here are some additional shots of the finished piece.

