This type of project is a really easy and cheap way to fill the spaces on your walls!!
I think this canvas cost me approx. $20, and I had the paint left over from feature walls and other jobs. Just choose a background colour that you like, then fill the space with simple shapes or lines... or whatever you like.
If you were not sure about painting something freehand, you could trace an object onto your canvas (for example, a tree-branch or a plate).