While I was mowing the lawn, I noticed Tom and the kids working on something in the high tunnel (someday we really are going to grow things in that thing). They were stringing up tarps and tacking plastic sheeting around the soccer goal.
They invited me to come in to their tent (I barely fit), and I discovered that a plastic sheeting tent produces the most lovely light diffusion. Really—every photographer should have their very own plastic hobo tent.