Here is a little DIY my house mates and I did to fill some of the blank walls in our house. Unfortunately I didn't get any pictures in the process of making them, but its pretty easy to do so hopefully pictures won't be necesary!
I should give some credit to my house mate Courtney who had the idea of making these!
-Wood plaques [you can find them at big craft stores like Joann's. You'll want something like this: http://www.joann.com/walnut-hollow-oak-rectangle-plaque-9-x12-/zprd_10480622a/ (we used a slightly smaller size)]
-Fabric in different colors and patterns that go well together
-Staple gun and staples
Step 1: Lay out your pieces of wood in a pattern you like and figure out which fabric you want on each plaque.
Step 2: Cut squares out of the fabric that are about 3 inches wider than the wood plaques.
Step 3: Staple one edge of the fabric to the underside of the plaque.
Step 4: Put a layer of glue all over the edges of the plaque. Stretch the fabric over the plaque, pressing the fabric onto the edge on the side where you stapled the fabric. Stretch the fabric tightly across the plaque and press it onto the edge opposite of the side you already finished. Staple this side. Do the two remaining sides. You will have to fold the corners like you are wrapping a book so that it looks neat. Make sure you use your fingernails to press the fabric down into all of the grooves along the edges.
Do this to all of your plaques and you're done!
Hopefully this makes sense without any pictures. I think in the end all of us ended up doing them in a way that was easiest for us, so you might end up figuring out an easier way to make it look neat.