Special note* Regular water will give the bubbles in the ice. If you boil the water first, it makes clear ice luminaries. Make sure the water is slightly hot when you pour it into the cup so you don't melt the plastic.
Spray the bottom of your luminary with PAM or a light coating of cooking oil so it doesn't stick to the freezer. Set the frozen luminary back in the freezer until ready to use. When night comes on Yule, take out the lanterns and place a small long burning candle inside. Enjoy!
I found another idea at Rhythm of the Home The Blog . Go check them out!
You can also do this with small cake molds or jello molds and place small jars in the center to hold the candles. Better yet place fruit, seeds, or veggie pieces in the water to freeze for wild animals to eat when the ice melts after use. A treat for both you and animals.