cool quilting tool
When you want to get a general sense of color and composition and you are tired of closing one eye and squinting like a pirate, looking through a door peephole is the way to go. You can find a door peephole (aka fire door viewer) on Amazon or at a hardware store for under $10.
It provides an extended fisheye view of your project and allows you to visually stand back and get a general lay of the land. I am currently working on a collage-y quilt, and looking through the peephole as I rearrange pieces helps me quickly make design decisions.
Beyond quilting, I could see a peephole being helpful to artists who work in all sorts of visual media.
Although it does eliminate squinting, you do still need to close one eye–I guess the pirate look is unavoidable!