My sewing room has been through m any changes in the past seven years. After we painted the walls two-toned green - with two colors of paint in the same roller pan - I wanted a trim between the lateral green striped effect on the top part of the wall and the scumbled green on the bottom of the wall. I was not happy with my first attempt to create a border - see photo; that's orange paint applied with a sponge cut in a rough square. At least I had some sort of border, though, right? I eventually decided I wanted a more structured design for a border/trim. So I scanned a real flower from our garden, dropped the scan into a Word Doc, then added a black border around the flower. I printed up a batch of these so I could glue them on the wall....
Trouble was, I had to cover up those ugly orange squares first. For this, I turned to my trusty old friend, brown wrapping paper. I cut the brown paper into strips, then glued it on the wall where I wanted the border to be. Then I glued the flowery squares over the brown paper.
PS: I love working with wallpaper paste; it's fun and easy to use.