Here is a basic tutorial for creating an interesting mozaic tile texture by using the “Render > Clouds” and “Distort > Wave” filters. In the end, you can colorize it using Hue/Saturation.
1. Create a new file of 200×200 pixel wide.
2. Create a new layer and fill it with black color.
3. Go to filter>render>clouds.
4. Press Ctrl+f for 3 times to have a picture like that.
5. Go to filter>disort>waves… and give the values like shown in the figure:
6. You are now having background like shown in the figure.
7. If you want, than you can color it by pressing Ctrl+U (hue/saturation box) click on colorize box and have a great colored background.