get yourself to the dollar store
Buy a couple packages of tissue paper, some white school glue, and a bag of balloons. Pronto. Here are the directions.
When we popped the balloons, there was a moment of sheer terror when some of the sides tried to collapse, but as soon as the balloon was removed the edges smoothed right back out.
I'm dreaming of about 30 of these hanging from the trees over the patio on a calm summer night, twinkly music and fireflies, perhaps a sangria in hand ...