One of the easiest things that you could do to customize your blog, besides change your header image, would be to change your background image. Sure, you could just set a background color, but why not bring in some texture?
Using full images can be problematic, as for the most part they will not conform to the size of everyone’s screen. Viewers with smaller screens will only see part of the image, and viewers with larger screens will see the image surrounded by white space. Even if you could get the image to stretch for larger screens, it would be distorted and pixellated, and this is where patterns come in.
In a sense, a pattern is a small image file which can be tiled seamlessly, thus adapting to any screen size. In WordPress, you can do this by uploading a small pattern image at Appearance -> Backgrounds in your Dashboard and choosing the “Tile” option under the Repeat section.
I did some digging earlier today for a personal project and found some great free patterns at Subtle Patterns and Background Labs, along with two great pattern builders at Pattern Cooler and BgPatterns. You could also build a simple noise-based background pattern in most photo editors by just dropping a noise texture into a small square with your desired color.
If you have ventured out on the hunt for background patterns before, we’d love to know which resources you prefer.