I bought two 6'X9' canvas drop clothes at Home Depot, cut them each into two panels of 3'X7'5". I hemmed the two sides that I had cut, the entire clothe comes hemmed so make as few cuts as possible to save on sewing time. I dyed the curtains just a little bit darker then the light canvas they came in. I sewed five plastic circles evenly on the back of the each curtain, about an inch from the top and about 1/4" from the edge (I bought these at the local fabric store). Then we penciled in 5 marks on the wall 4" from the top of the window and evenly spaced to cover all the open wall between the windows. All I need to do yet is steam them a little and decide if I want to add fabric to the bottom like my sample shot I posted a couple weeks ago.
Before:
After: