Parallel straight lines whether horizontal or vertical fit this category.
Then the opposite direction.
There's a boxed scroll idea..
By the way... I'm creating this sampler on white silk. I've got a bigger art quilt project that is challenging me to use a silk top, so I thought I better play a bit first. So I am doing 2 things at once here by practicing stitch outs. Happy Quilting. I'll add some Harmonizing stitches next time.