My latest one - sorry, digital cam is on the blink, has two panes, one up and one down. I got some decorative curly wood embelishments at Lowes and added them to the frame, then painted, aged and crackled the whole frame. On the top pane I wrote in gold lettering "French Quarter" and inside behind the bottom pane I put an old linen dresser cloth with a lace edge. The whole thing looks like an antique window from a New Orleans hotel or something washed up from Katrina.

Another window thing that sold a lot was buying reproduction vintage tin signs on the internet and just gluing or nailing them right to the weatherbeaten window. My best one says "Aunt Sally's Pies" with a pix of a piece of pie. I nailed it diagonaly across the whole window frame, no new painting or refinishing. It looks like it came out of a roadhouse cafe. I could sell more, but as soon as people try to pick one up, they realize how much the darn things weigh. Also makes them a poor choice for EBay. Good luck with the greenhouse, though. Should work out well.