I often create textures and backgrounds by layering grunge brushes in different colors and at different blend modes.
This design uses the Gouache Grunge No. 8 Photoshop Brushes.
These little design experiments can be further developed into other designs. Below, I used the design as a 4-way pattern. (4-ways are created by flipping the image horizontally and then vertically to create a mirrored design.)
Creating these are fabulous, quick playtime explorations. I seldom have a final vision, I just start stamping brushes one into each layer and then playing with color, placement, and blend modes.
Give it a try - it's addicting!