These adorable luminaries are made from water balloons and wax. They look fairly easy to make too. Instructions can be found at... www.candletech.com
This tutorial is a little more involved that the above ones, but the results are wonderful. Find out how to make the luminaries shown below at www.modpodgerocksblog.com
This example below is made for Halloween, but I'm thinking if you used other colors, you could use it any time of the year. The tutorial can be found at www.thelongthread.com
Hope you're inspired to try your hand at making some luminaries. Enjoy your summer!