To create a simple checker pattern for a header: pick the Pencil Tool and add two 2-pixel dots touching corners, turn off the background and select the dots, then choose Define Pattern from the Edit menu.

1. Create A Texture Pattern:
8

2. Create A Texture
Pattern:
Now create a simple checker pattern and apply to
the header.
Pick the Pencil Tool, set the brush size to 2 pixels
and add two dots that are touching each others
corners.
Turn off the background and select the dots.
Choose Edit > Define Pattern.