Once you’ve followed this tutorial, you’ll be able to apply the steps to make your own patterns for use in Photoshop once you’re bored of checkers.
Step 1 Copy and paste this image into PS:
Step 2 Go to Edit > Define Pattern, and rename the pattern if you like then press Ok.
Step 3 Open up a new image, then click the paint bucket.
Step 4 At the top of the screen, change the Fill to Pattern, then click the tiny arrow and choose your new pattern.
Step 5 Finally, click your image to floodfill it with your new pattern. See my Colourising tutorial if you don’t like the colour, or use the Magic Wand and Floodfill Bucket to alter according to your needs. You can then choose to save your finished patterns so you don’t have to go through the process again.