I used to have to use a hallway wall as my design wall - no way to get 10' back from that! (I probably can get about 8 feet back from my new setup though - a vast improvement!)
I use the camera. I get back as far as I can and snap a picture in color and for some quilts another in black & white. If anything jars the eye I go back and re-arrange.
I'll take 20-30 sets of photos for a stack & whack - I have to fuss with those FOREVER before I'm happy. Thank goodness for digital cameras!