One day I had a bag full of unlabeled embroidery floss from old projects and wanted to find a use for it. I stitched diagonal rows and a plaid pattern started taking shape. If you like repetitive patterns that don't require much thought, use up a good amount of floss, and result in a dense pattern, give this a try.
And for bonus points, sit your camera directly on the finished piece and snap a picture. The macro image may turn out to be more interesting than the original cross stitch.