I have a lot of texture work in my art mostly because it forces the piece in a more traditional direction, rather then something obviously Photoshop. I add layers of dirt, concrete, sand, rock faces, bushes, splatters, scribbles or whatever I can find that would add more dimension and emotion to my work.
Working with textures is a big part of my creative process and I hardly got to touch on it in the previous posts, mostly because adjustments are being made the entire time I work. So I thought it would be easier to show a simple texture in action rather then explaining. You can download the ZIP file (3.06 mb) which contains a 72dpi PSD file with my layers and setting intact. It only contains four layers that, when overlayed and adjusted, create a nice splattery background texture. I used this particular combination in a lot of the recent composite work.
So, open up the PSD and have a look at my layer settings and opacities to see how it works. Have fun.