Create Repitition and Rhythm using Adobe Illustrator Patterns.

Below is a great tutorial showing how to create patterns with Adobe Illustrator:



Here is the hyperlink:
http://tv.adobe.com/watch/visual-design-cs6/creating-a-simple-pattern/

Here is another link explaining the design principle "Rythem":http://www.sophia.org/tutorials/design-in-art-repetition-pattern-and-rhythm

Use Adobe Illustrator to create several 12" x 12" patterns. Take it another step and create an emphasis or focus for the pattern composition.